Cosmologists

"Μη φοβάσαι τον θεό, Μην ανησυχείτε για το θάνατο. Αυτό που είναι καλό είναι εύκολο να αποκτηθεί, και Αυτό που είναι τρομερό είναι εύκολο να υπομείνει."

"Δικαιοσύνης καρπὸς μέγιστος ἀταραξία."

"Luxurious food and drinks, in no way protect you from harm. Wealth beyond what is natural, is no more use than an overflowing container. Real value is not generated by theaters, and baths, perfumes or ointments, but by philosophy."

"Let no one be slow to seek wisdom when he is young nor weary in the search of it when he has grown old. For no age is too early or too late for the health of the soul. And to say that the season for studying philosophy has not yet come, or that it is past and gone, is like saying that the season for happiness is not yet or that it is now no more. Therefore, both old and young alike ought to seek wisdom, the former in order that, as age comes over him, he may be young in good things because of the grace of what has been, and the latter in order that, while he is young, he may at the same time be old, because he has no fear of the things which are to come. So we must exercise ourselves in the things which bring happiness, since, if that be present, we have everything, and, if that be absent, all our actions are directed towards attaining it."

"τὸ φρικωδέστατον οὖν τῶν κακῶν ὁ θάνατος οὐθὲν πρὸς ἡμᾶς͵ ἐπειδήπερ ὅταν μὲν ἡμεῖς ὦμεν͵ ὁ θάνατος οὐ πάρεστιν͵ ὅταν δὲ ὁ θάνατος παρῇ͵ τόθ΄ ἡμεῖς οὐκ ἐσμέν."

"He who is not satisfied with a little, is satisfied with nothing."

"Self-sufficiency is the greatest of all wealth."

"A happy and eternal being has no trouble himself and brings no trouble upon any other being; hence he is exempt from movements of anger and partiality, for every such movement implies weakness. (1)"

"Οὐκ ἔστιν ἡδέως ζῆν ἄνευ τοῦ φρονίμως καὶ καλῶς καὶ δικαίως, οὐδὲ φρονίμως καὶ καλῶς καὶ δικαίως ἄνευ τοῦ ἡδέως. ὅτῳ δὲ τοῦτο μὴ ὑπάρχει ἐξ οὗ ζῆν φρονίμως, καὶ καλῶς καὶ δικαίως ὑπάρχει, οὐκ ἔστι τοῦτον ἡδέως ζῆν."

"No pleasure is in itself evil, but the things which produce certain pleasures entail annoyances many times greater than the pleasures themselves. (8)"

"It is impossible for someone to dispel his fears about the most important matters if he doesn't know the nature of the universe but still gives some credence to myths. So without the study of nature there is no enjoyment of pure pleasure. (12)"

"The wealth required by nature is limited and is easy to procure; but the wealth required by vain ideals extends to infinity. (15)"

"Chance seldom interferes with the wise man; his greatest and highest interests have been, are, and will be, directed by reason throughout his whole life. (16)."

"Ὁ δίκαιος ἀταρακτότατος, ὁ δ᾽ ἄδικος πλείστης ταραχῆς γέμων."

"The flesh receives as unlimited the limits of pleasure; and to provide it requires unlimited time. But the mind, intellectually grasping what the end and limit of the flesh is, and banishing the terrors of the future, procures a complete and perfect life, and we have no longer any need of unlimited time. Nevertheless the mind does not shun pleasure, and even when circumstances make death imminent, the mind does not lack enjoyment of the best life. (20)"

"We must consider both the ultimate end and all clear sensory evidence, to which we refer our opinions; for otherwise everything will be full of uncertainty and confusion. (22)"

"If you reject absolutely any single sensation without stopping to discriminate with respect to that which awaits confirmation between matter of opinion and that which is already present, whether in sensation or in feelings or in any immediate perception of the mind, you will throw into confusion even the rest of your sensations by your groundless belief and so you will be rejecting the standard of truth altogether. If in your ideas based upon opinion you hastily affirm as true all that awaits confirmation as well as that which does not, you will not escape error, as you will be maintaining complete ambiguity whenever it is a case of judging between right and wrong opinion. (24)"

"Of all the means which wisdom acquires to ensure happiness throughout the whole of life, by far the most important is friendship. (28)"

"Of our desires some are natural and necessary, others are natural but not necessary; and others are neither natural nor necessary, but are due to groundless opinion. (29)"

"Natural justice is a symbol or expression of usefulness, to prevent one person from harming or being harmed by another. (31)"

"Those animals which are incapable of making binding agreements with one another not to inflict nor suffer harm are without either justice or injustice; and likewise for those peoples who either could not or would not form binding agreements not to inflict nor suffer harm. (32)"

"It is impossible for a man who secretly violates the terms of the agreement not to harm or be harmed to feel confident that he will remain undiscovered, even if he has already escaped ten thousand times; for until his death he is never sure that he will not be detected. (35)"

"Among the things held to be just by law, whatever is proved to be of advantage in men's dealings has the stamp of justice, whether or not it be the same for all; but if a man makes a law and it does not prove to be mutually advantageous, then this is no longer just. And if what is mutually advantageous varies and only for a time corresponds to our concept of justice, nevertheless for that time it is just for those who do not trouble themselves about empty words, but look simply at the facts. (37)"

"Where without any change in circumstances the things held to be just by law are seen not to correspond with the concept of justice in actual practice, such laws are not really just; but wherever the laws have ceased to be advantageous because of a change in circumstances, in that case the laws were for that time just when they were advantageous for the mutual dealings of the citizens, and subsequently ceased to be just when they were no longer advantageous. (38)"

"Those who were best able to provide themselves with the means of security against their neighbors, being thus in possession of the surest guarantee, passed the most agreeable life in each other's society; and their enjoyment of the fullest intimacy was such that, if one of them died before his time, the survivors did not mourn his death as if it called for sympathy. (40)"

"The end of living, or the ultimate good, which is to be sought for its own sake, according to the universal opinion of mankind, is happiness; yet men, for the most part, fail in the pursuit of this end, either because they do not form a right idea of the nature of happiness, or because they do not make use of proper means to attain it."

"Since it is every man's interest to be happy through the whole of life, it is the wisdom of every one to employ philosophy in the search of felicity without delay; and there cannot be a greater folly, than to be always beginning to live."

"The happiness which belongs to man, is that state in which he enjoys as many of the good things, and suffers as few of the evils incident to human nature as possible; passing his days in a smooth course of permanent tranquility. A wise man, though deprived of sight or hearing, may experience happiness in the enjoyment of the good things which yet remain; and when suffering torture, or laboring under some painful disease, can mitigate the anguish by patience, and can enjoy, in his afflictions, the consciousness of his own constancy."

"Pleasure, or pain, is not only good, or evil, in itself, but the measure of what is good or evil, in every object of desire or aversion; for the ultimate reason why we pursue one thing, and avoid another, is because we expect pleasure from the former, and apprehend pain from the latter. If we sometimes decline a present pleasure, it is not because we are averse to pleasure itself, but because we conceive, that in the present instance, it will be necessarily connected with a greater pain. In like manner, if we sometimes voluntarily submit to a present pain, it is because we judge that it is necessarily connected with a greater pleasure."

"There are two kinds of pleasure: one consisting in a state of rest, in which both body and mind are undisturbed by any kind of pain; the other arising from an agreeable agitation of the senses, producing a correspondent emotion in the soul. It is upon the former of these that the enjoyment of life chiefly depends. Happiness may therefore be said to consist in bodily ease, and mental tranquility."

"When pleasure is asserted to be the end of living, we are not then to understand that violent kind of delight or joy which arises from the gratification of the senses and passions, but merely that placid state of mind, which results from the absence of every cause of pain or uneasiness. Those pleasures, which arise from agitation, are not to be pursued as in themselves the end of living, but as means of arriving at that stable tranquility, in which true happiness consists. It is the office of reason to confine the pursuit of pleasure within the limits of nature, in order to the attainment of that happy state, in which the body is free from every kind of pain, and the mind from all perturbation. This state must not, however, be conceived to be perfect in proportion as it is inactive and torpid, but in proportion as all the functions of life are quietly and pleasantly performed. A happy life neither resembles a rapid torrent, nor a standing pool, but is like a gentle stream, that glides smoothly and silently along."

"This happy state can only be obtained by a prudent care of the body, and a steady government of the mind. The diseases of the body are to be prevented by temperance, or cured by medicine, or rendered tolerable by patience."

"Against the diseases of the mind, philosophy provides sufficient antidotes. The instruments which it employs for this purpose are the virtues; the root of which, whence all the rest proceed, is prudence. This virtue comprehends the whole art of living discreetly, justly, and honorably, and is, in fact, the same thing with wisdom. It instructs men to free their understandings from the clouds of prejudice; to exercise temperance and fortitude in the government of themselves: and to practice justice towards others. Although pleasure, or happiness, which is the end of living, be superior to virtue, which is only the means, it is every one's interest to practice all the virtues; for in a happy life, pleasure can never be separated from virtue."

"A prudent man, in order to secure his tranquility, will consult his natural disposition in the choice of his plan of life. If, for example, he be persuaded that he should be happier in a state of marriage than in celibacy, he ought to marry; but if he be convinced that matrimony would be an impediment to his happiness, he ought to remain single."

"Temperance is that discreet regulation of the desires and passions, by which we are enabled to enjoy pleasures without suffering any consequent inconvenience. They who maintain such a constant self-command, as never to be enticed by the prospect of present indulgence, to do that which will be productive of evil, obtain the truest pleasure by declining pleasure."

"Since, of desires some are natural and necessary; others natural, but not necessary; and others neither natural nor necessary, but the offspring of false judgment; it must be the office of temperance to gratify the first class, as far as nature requires: to restrain the second within the bounds of moderation; and, as to the third, resolutely to oppose, and, if possible, entirely repress them."

"Sobriety, as opposed to inebriety and gluttony, is of admirable use in teaching men that nature is satisfied with a little, and enabling them to content themselves with simple and frugal fare."

"Continence is a branch of temperance, which prevents the diseases, infamy, remorse, and punishment, to which those are exposed, who indulge themselves in unlawful amours."

"Gentleness, as opposed to an irascible temper, greatly contributes to the tranquility and happiness of life, by preserving the mind from perturbation, and arming it against the assaults of calumny and malice."

"A wise man, who puts himself under the government of reason, will be able to receive an injury with calmness, and to treat the person who committed it with lenity; for he will rank injuries among the casual events of life, and will prudently reflect that he can no more stop the natural current of human passions, than he can curb the stormy winds."

"Moderation, in the pursuit of honors or riches, is the only security against disappointment and vexation. A wise man, therefore, will prefer the simplicity of rustic life to the magnificence of courts."

"Fortitude, the virtue which enables us to endure pain, and to banish fear, is of great use in producing tranquility. Philosophy instructs us to pay homage to the gods, not through hope or fear, but from veneration of their superior nature. It moreover enables us to conquer the fear of death, by teaching us that it is no proper object of terror; since, whilst we are, death is not, and when death arrives, we are not: so that it neither concerns the living nor the dead."

"Justice respects man as living in society, and is the common bond without which no society can subsist."

"Nearly allied to justice are the virtues of beneficence, compassion, gratitude, piety, and friendship."

"A true friend will partake of the wants and sorrows of his friend, as if they were his own; if he be in want, he will relieve him; if he be in prison, he will visit him; if he be sick, he will come to him; nay-situations may occur, in which he would not scruple to die for him. It cannot then be doubted, that friendship is one of the most useful means of procuring a secure, tranquil, and happy life."

"Is God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God?"

"For if they imagine infinite spaces of time before the world, during which God could not have been idle, in like manner they may conceive outside the world infinite realms of space, in which, if any one says that the Omnipotent cannot hold His hand from working, will it not follow that they must adopt Epicurus' dream of innumerable worlds? with this difference only, that he asserts that they are formed and destroyed by the fortuitous movements of atoms, while they will hold that they are made by God's hand, if they maintain that, throughout the boundless immensity of space, stretching interminably in every direction round the world, God cannot rest, and that the worlds which they suppose Him to make cannot be destroyed. ... there is no place beside the world ...no time before the world."

"Epicurus may therefore turn and twist as he likes, deny Providence, deny the punishments and rewards of another life; make justice, friendship, and every other virtue serve pleasure; reduce the human intellect to combinations of atoms, and aspire, as the highest of goods, to the condition of the beast, which always finds itself in the same place, alone against all, alone in all places, against all times and against all men or the whole human race, which never ceases to proclaim a rewarding and avenging God, the immortality of the soul and the eternal distinction between good and evil, and thus condemns the Epicurean system as equally false and shameful. (vol. I, p. 774)"

"Verily, no modern atheist, Mr. Huxley included, can outvie Epicurus in materialism; he can but mimic him. And what is his “ protoplasm.” but a rechauffe of the speculations of the Hindu Swabhavikas or Pantheists, who assert that all things, the gods as well as men and animals, are born from Swabhava or their own nature?! As to Epicurus, this is what Lucretius makes him say: “The soul, thus produced, must be material, because we trace it issuing from a material source; because it exists, and exists alone in a material system ; is nourished by material food ; grows with the growth of the body; becomes matured with its maturity; declines with its decay; and hence, whether belonging to man or brute, must die with its death.” Nevertheless, we would remind the reader that Epicurus is here speaking of the Astral Soul, not of Divine Spirit. Still, if we rightly understand the above, Mr. Huxley's “mutton protoplasm” is of a very ancient origin, and can claim for its birthplace, Athens, and for its cradle, the brain of old Epicurus. p. 250"

"Truly says Cudworth that the greatest ignorance of which our modern wiseacres accuse the ancients is their belief in the soul's immortality. Like the old skeptic of Greece, our scientists—to use an expression of the same Dr. Cudworth—are afraid that if they admit spirits and apparitions they must admit a God too; and there is nothing too absurd, he adds, for them to suppose, in order to keep out the existence of God. The great body of ancient materialists, skeptical as they now seem to us, thought otherwise, and Epicurus, who rejected the soul's immortality, believed still in a God, and Demokritus fully conceded the reality of apparitions. The preexistence and God-like powers of the human spirit were believed in by most all the sages of ancient days. p. 251"

"Epicurus says, no life can be pleasant except a virtuous life; and he charges you to avoid whatever maybe calculated to create disquiet in the mind, or give pain to the body."

"We know, that of all living beings man is the best formed, and, as the gods belong to this number, they must have a human form. ... I do not mean to say that the gods have body and blood in them; but I say that they seem as if they had bodies with blood in them. . . , Epicurus, for whom hidden things were as tangible as if he had touched them with his finger, teaches us that gods are not generally visible, but that they are intelligible; that they are not bodies having a certain solidity . . . but that we can recognize them by their passing images; that as there are atoms enough in the infinite space to produce such images, these are produced before us . . . and make us realize what are these happy, immortal beings."

"We cannot quote from his own works, in his own words, because, although he wrote very much, only a summary of his writings has come to us uninjured; but his doctrines have been so fully investigated and treated on, both by his opponents and his disciples, that there is no difficulty or doubt as to the principles inculcated in the school of Epicurus...."

"The sum of his doctrine concerning philosophy, in general, is this: Philosophy is the exercise of reason in the pursuit and attainment of a happy life; whence it follows, that those studies which conduce neither to the acquisition nor the enjoyment of happiness are to be dismissed as of no value. The end of all speculation ought to be, to enable men to judge with certainty what is to be chosen, and what to be avoided, to preserve themselves free from pain, and to secure health of body, and tranquillity of mind. True philosophy is so useful to every man, that the young should apply to it without delay, and the old should never be weary of the pursuit; for no man is either too young or too old to correct and improve his mind, and to study the art of happiness. Happy are they who possess by nature a free and vigorous intellect, and who are born in a country where they can prosecute their inquiries without restraint: for it is philosophy alone which raises a man above vain fears and base passions, and gives him the perfect command of himself."

"As nothing ought to be dearer to a philosopher than truth, he should, pursue it by the most direct means, devising no actions himself, nor suffering himself to be imposed upon by the fictions of others, neither poets, orators, nor logicians, making no other use of the rules of rhetoric or grammar, than to enable him to speak or write with accuracy and perspicuity, and always preferring a plain and simple to an ornamented style. Whilst some doubt of everything, and others profess to acknowledge everything, a wise man will embrace such tenets, and only such as are built upon experience, or upon certain and indisputable axioms."

"Ergo vivida vis animi pervicit, et extra Processit longe flammantia moenia mundi Atque omne immensum peragravit, mente animoque."

"The system of Democritus was adopted by Epicurus, but not because Epicurus had any keenness of scientific vision. On the contrary, Epicurus, the Herbert Spencer of antiquity, was in his natural philosophy an encyclopedia of second-hand knowledge."

""The Epicureans in their writings established this precept: always keep in your mind one of those ancients who practiced virtue." - Marcus Aurelius (The Essential Marcus Aurelius)"

""The thought for today is one which I discovered in Epicurus; for I am wont to cross over even into the enemy’s camp – not as a deserter but as a scout. (Letters, 2)" - Seneca (What Seneca Really Said about Epicureanism)"

"τὰ ὄντα ἰέναι τε πάντα καὶ μένειν οὐδέν"

"πάντα χωρεῖ καὶ οὐδὲν μένει"

"δὶς ἐς τὸν αὐτὸν ποταμὸν οὐκ ἂν ἐμβαίης."

"χαλεπώτερον ἡδονῇ μάχεσθαι ἢ θυμῷ"

"τὴν μεταβολὴν ὁδὸν ἄνω κάτω, τόν τε κόσμον γίνεσθαι κατ' αὐτήν."

"αἰὼν παῖς ἐστι παίζων, πεσσεύων· παιδὸς ἡ βασιληίη."

"# The Cosmos is child's play: a child playing chess as King."

"#* Using English idioms to parallel the original's wordplay."

"# History is a child building a sand-castle by the sea, and that child is the whole majesty of man’s power in the world."

"#* A very free translation, as quoted in Contemporary Literature in Translation (1976), p. 21"

"# A lifetime is a child playing, playing checkers; the kingdom belongs to a child."

"#* As quoted in The Beginning of All Wisdom: Timeless Advice from the Ancient Greeks (2003) by Steven Stavropoulos, p. 95"

"# Time is a game played beautifully by children."

"#* A free translation, as quoted in Fragments (2001) translated by Brooks Haxton"

"# Lifetime is a child at play, moving pieces in a game. Kingship belongs to the child."

"#* As quoted in The Art and Thought of Heraclitus (1979) translated by Charles H. Kahn"

"χρὴ γὰρ εὖ μάλα πολλῶν ἴστορας φιλοσόφους ἄνδρας εἶναι"

"Πόλεμος πάντων μὲν πατήρ ἐστι πάντων δὲ βασιλεύς, καὶ τοὺς μὲν θεοὺς ἔδειξε τοὺς δὲ ἀνθρώπους, τοὺς μὲν δούλους ἐποίησε τοὺς δὲ ἐλευθέρους."

"# War is the father and king of all: some he has made gods, and some men; some slaves and some free."

"# War is the father and king of all, and has produced some as gods and some as men, and has made some slaves and some free. (G. T. W. Patrick, 1889)"

"#* Hippolytus, Ref. haer. ix. 9 (Fragment 53). Context: "And that the father of all created things is created and uncreated, the made and the maker, we hear him (Heraclitus) saying, 'War is the father and king of all,' etc.""

"#* Plutarch, de Iside 48, p. 370. Context, see frag. 43."

"#* Proclus in Tim. 54 A (comp. 24 B)."

"#* Compare Chrysippus from Philodem. P. eusebeias, vii. p. 81, Gomperz."

"#* Lucianus, Quomodo hist. conscrib. 2; Idem, Icaromen 8."

"# See also: πόλεμος πάντων μὲν πατήρ ἐστι, πάντων δὲ βασιλεύς"

"# Martin Heidegger, Parmenides (1942–1943)"

"Τίς γὰρ αὐτῶν νόος ἢ φρήν; [δήμων] ἀοιδοῖσι ἕπονται καὶ διδασκάλῳ χρέωνται ὁμίλῳ, οὐκ εἰδότες ὅτι πολλοὶ κακοὶ ὀλίγοι δὲ ἀγαθοί. αἱρεῦνται γὰρ ἓν ἀντία πάντων οἱ ἄριστοι, κλέος ἀέναον θνητῶν, οἱ δὲ πολλοὶ κεκόρηνται ὅκωσπερ κτήνεα."

"# The best people renounce all for one goal, the eternal fame of mortals; but most people stuff themselves like cattle."

"# For what sense or understanding have they? They follow minstrels and take the multitude for a teacher, not knowing that many are bad and few good. For the best men choose one thing above all – immortal glory among mortals; but the masses stuff themselves like cattle. (G.T.W. Patrick, 1889)"

"#: "The passage is restored as above by Bernays (Heraclitea i. p. 34), and Bywater (p. 43), from the following sources:"

"#:* Clement of Alex. Strom. v. 9, p. 682."

"#:* Proclus in Alcib. p. 255 Creuzer, = 525 ed. Cous. ii."

"#:* Clement of Alex. Strom. iv. 7, p. 586.""

"Ten thousand do not turn the scale against a single man of worth."

"Greater fates gain greater rewards"

"The many are mean; only the few are noble."

"τοῦ λόγου δ' ἐόντος ξυνοῦ ζώουσιν οἱ πολλοὶ ὡς ἰδίαν ἔχοντες φρόνησιν"

"οὐ γὰρ φρονέουσι τοιαῦτα [οἱ] πολλοί, ὁκόσοι ἐγκυρεῦσιν, οὐδὲ μαθόντες γινώσκουσιν, ἑωυτοῖσι δὲ δοκέουσι."

"συνάψιες ὅλα καὶ οὐχ ὅλα, συμφερόμενον διαφερόμενον, συνᾷδον διᾷδον, καὶ ἐκ πάντων ἓν καὶ ἐξ ἑνὸς πάντα."

"ποταμοῖσι τοῖσιν αὐτοῖσιν ἐμϐαίνουσιν, ἕτερα καὶ ἕτερα ὕδατα ἐπιρρεῖ."

"ἐὰν μὴ ἔλπηται ἀνέλπιστον, οὐκ ἐξευρήσει"

"ἄνθρωπος ἐν εὐφρόνῃ φάος ἅπτεται ἑαυτῷ [ἀποθανὼν] ἀποσβεσθεὶς"

"κόσμον τόνδε, τὸν αὐτὸν ἁπάντων, οὔτε τις θεῶν οὐτε ἀνθρώπων ἐποίησεν, ἀλλ' ἦν ἀεὶ καὶ ἔστιν καὶ ἔσται πῦρ ἀείζωον, ἁπτόμενον μέτρα καὶ ἀποσβεννύμενον μέτρα"

"ἓν τὸ σοφὸν μοῦνον λέγεσθαι οὐκ ἐθέλει καὶ ἐθέλει Ζηνὸς ὄνομα"

"πολυμαθίη νόον οὐ διδάσκει"

"μάχεσθαι χρὴ τὸν δῆμον ὑπὲρ τοῦ νόμου ὅκωσπερ τείχεος"

"B49a. potamois tois autois …"

"Into the same rivers we step and do not step, we are and are not. (Heraclitus Homericus)"

"οὐκ ἐμοῦ, ἀλλὰ τοῦ λόγου ἀκούσαντας ὁμολογεῖν σο­φόν ἐστιν ἓν πάντα εἶναί"

"ὁδὸς ἄνω κάτω μία καὶ ὡυτή"

"ὁ θεὸς ἡμέρη εὐφρόνη, χειμὼν θέρος, πόλεμος εἰρήνη, κόρος λιμός"

"ταὐτό τ' ἔνι ζῶν καὶ τεθνηκὸς καὶ [τὸ] ἐγρηγορὸς καὶ καθεῦδον καὶ νέον καὶ γηραιόν"

"τοῖς ἐγρηγορόσιν ἕνα καὶ κοινὸν κόσμον εἶναι, τῶν δὲ κοιμωμένων ἕκαστον εἰς ἴδιον ἀποστρέφεσθαι"

"ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ"

"Although the Law of Reason is common, the majority of people live as though they had an understanding of their own."

"Men are at variance with the one thing with which they are in the most unbroken communion, the reason that administers the whole universe."

"νέκυες γὰρ κοπρίων ἐκβλητότεροι"

"κύνες γὰρ καὶ βαΰζουσινὃν, ἂν μὴ γινώσκωσι."

"ἀμαθίην κρύπτειν ἄμεινον"

"ἀνθρώποις γίνεσθαι ὁκόσα θέλουσιν οὐκ ἄμεινον"

"Speaking with sense we must fortify ourselves in the common sense of all, as a city is fortified by its law, and even more forcefully. For all human laws are nourished by the one divine law. For it prevails as far as it will and suffices for all and is superabundant."

"All human laws are nourished by one divine law."

"ἦθος ἀνθρώπῳ δαίμων"

"φύσις κρύπτεσθαι φιλεῖ"

"I have sought for myself."

"It pertains to all men to know themselves and to learn self-control."

"Opposition brings concord. Out of discord comes the fairest harmony."

"Many statements paraphrase or extend upon his famous assertions that "everything changes" in ways which arguably diverge from valid translation, and yet have become widely attributed to Heraclitus:"

"Of Every One-Hundred Men, Ten shouldn't even be there, Eighty are nothing but targets, Nine are real fighters... We are lucky to have them... They make the battle. Ah but the One, One of them is a Warrior... and He will bring the others back."

"It was not Zeno, the founder of the Stoics, alone, who taught that the Universe evolves, and its primary substance is transformed from the state of fire into that of air, then into that of water, etc. Heraclitus of Ephesus maintained that the one principle that underlies all phenomena in Nature is fire. The intelligence that moves the Universe is fire, and fire is intelligence. And while Anaximenes said the same of air, and Thales of Miletus (600 years b.c.) of water, the Esoteric Doctrine reconciles all these philosophers, by showing that though each was right, the system of none was complete."

"In... Heraclitus... Becoming occupies the foremost place. He regarded that which moves, the fire, as the basic element. The difficulty, to reconcile the... one fundamental principle with the infinite variety of phenomena, is solved... by recognizing... strife of... opposites is... a kind of harmony. ...[T]he world is ...one and many ..."the opposite tension" of ...opposites ...constitutes the unity of the One. He says: "...war is common to all and strife is justice ...all things come into being and pass away through strife." ...[T]hat infinite and eternal undifferentiated Being ...cannot ...explain the infinite variety of things. This leads to the antithesis of Being and Becoming and ...to the solution of Heraclitus ...change ...is the fundamental principle; the "imperishable change, that renovates the world," as the poets have called it. But ...change ...is not a material cause and therefore is represented ...by the fire ...both matter and a moving force. ...[[Physics|[P]hysics]] is ...extremely near to ...Heraclitus ...[i]f we replace ..."fire" by ..."energy" ...Energy is a substance, since its total ...does not change, and ...elementary particles can ...be made from this ...Energy may be called the fundamental cause for all change in the world. ...Energy is ...that which moves; it may be called the primary cause of all change, and ...can be transformed into matter or heat or light. The strife between opposites in the philosophy of Heraclitus can be found in the strife between two different forms of energy."

"[With Heraclitus] we see land; there is no proposition of Heraclitus which I have not adopted in my Logic."

"I walked on to the next corner, sat on a bench at a bus stop, and read in my new book about Heraclitus. All things flow like a river, he said; nothing abides. Parmenides, on the other hand, believed that nothing ever changed, it only seemed so. Both views appealed to me."

"In other countries, too, the idea of a creation was sternly rejected, as, for instance, by Heraclitus, who declares that no god and no man made this world, but that it was always and is and will be, an eternal fire, assuming forms and destroying them. And this protest, it should be remembered, came from a man who was able to say with equal honesty that 'God is day and night, winter and summer, war and peace, satiety and hunger—and that he is called according to the pleasure of every one.'"

"Herakleitos, about 460 B.C., one of the boldest thinkers of ancient Greece, declared that Homer deserved to be ejected from public assemblies and flogged..."

"If the flow is steady, the field velocity vectors and the system of streamlines remain unaffected by the progress of time. Looking at the vector field and its streamlines we do not notice any change. Yet if we could distinguish the different particles of fluid from each other, we could observe incessant change... We have here two aspects of a steady flow, one of unchanging persistence, the other of incessant change. ...Heraclitus was called the "Dark Philosopher"; his views of human affairs were sombre and his sayings obscure. ... "You cannot look twice at the same river; for fresh waters are ever flowing in." "We look and do not look at the same rivers; we are, and we are not." What is the intended meaning of these sentences? I do not venture to find out. Yet I think that the originator of these senteces came pretty close to formulating the concept "steady flow of a fluid.""

"When... Heraclitus names the world an ever-living fire that... extinguishes itself and again kindles itself, when... all is exchanged for fire and fire for all... he can only understand by this that fire, this restless, all-consuming, all-transmuting, and equally (in heat) all-vivifying element, represents the constant force of this eternal alteration and transformation, the notion of life, in the most vivid and energetic manner. ...the means of which the power of motion that is precedent to all matter avails itself for the production of the living process of things. Heraclitus... explains the multiplicity of things... [fire] condenses itself into material elements, first air, then water, then earth. ...These two processes of extinction and ignition... alternate... in perpetual rotation with each other and... in stated periods the world resolves itself into the primal fire, in order to re-create itself out of it again. ...[F]ire is to him... the principle of movement, of physical as of spiritual vitality; the soul itself is a fiery vapour; its power and perfection depend on its being pure from all grosser and duller elements."

"The part I understand is excellent, and so too is, I dare say, the part I do not understand; but it needs a Delian diver to get to the bottom of it."

"I cannot approve of Heraclitus, who, being self-taught and arrogant, said, "I have explored myself." Nor can I praise him for hiding his poem in the temple of Artemis, in order that it might be published afterwards as a mystery; and those who take an interest in such things say that Euripides the tragic poet came there and read it, and, gradually learning it by heart, carefully handed down to posterity this darkness of Heraclitus."

"If neither sub-atomic particles nor organic species exemplify the 'permanent entities' of Greek metaphysics, what else in the real world does so? ...Two hundred years of historical research have had their effect. Whether we turn to social or intellectual history, evolutionary zoology, historical geology or astronomy—whether we consider explanatory theories or star-clusters, societies or cultures, languages or disciplines, organic species or the Earth itself—the verdict is not Parmenidean but Heraclitean. As we now understand it, nothing in the empirical world possesses the permanent unchanging identity which all Greek natural philosophers (the Epicureans apart) presupposed in the ultimate elements of Nature. So, if we... are to entertain metaphysical thoughts about the nature of things-in-general consistent with the rest of our late-twentieth-century ideas, we must explore the consequences of the modern, post-Darwinian or 'populational' approach, as applied not just to species, but to historical entities of all kinds. Confronted with the question, 'How do permanent entities preserve their identity through all their apparent changes?', we must simply deny the validity of the question itself. In its place, we must substitute the question, 'How do historical entities maintain their coherence and continuity, despite all the real changes they undergo?'"

"[L]ikely he was not a disciple of any one; but... he was acquainted both with the Milesian cosmology and with the poems of Xenophanes. He... knew something of the theories taught by Pythagoras (fr. 17)."

"[P]erhaps... he belonged to the ancient royal house and resigned the nominal position of in favour of his brother."

"We do not know the title of the work of Herakleitos... We are told that it was divided into three discourses: one dealing with the universe, one political, and one theological. It is not likely that this division is due to Herakleitos... The style... is... obscure, and... later... got him the nickname... "the Dark.""

"[F]ragments about the Delphic god and the Sibyl (frs. 11 and 12) seem to show... an oracular style... [I]t was the manner of the time. The stirring events of the age, and... religious revival, gave... a prophetic tone to all the leaders of thought. Pindar and Aischylos have it too. They all feel... inspired. It is also the age of... individualities... apt to be solitary and disdainful. Herakleitos... [writes] If men cared to dig for the gold they might find it (fr. 8); if not, they must be content with straw (fr. 51)."

"Theophrastos... said... the headstrong temperament of Herakleitos sometimes led him into incompleteness and inconsistencies of statement. ...[A] very different thing from studied obscurity and the disciplina arcana sometimes attributed to him; if Herakleitos does not go out of his way to make his meaning clear, neither does he hide it (fr. 11)."

"[S]ome... fragments are far from clear, and there are probably not a few of which the meaning will never be recovered. ...[T]he doxographers... are far less instructive with... Herakleitos... [T]he two accounts of... Herakleitos... in Diogenes, which goes back to the Vetusta Placita... is... pretty full and accurate. All our other sources are... tainted."

"Most... commentators on Herakleitos... in Diogenes were Stoics, and... their paraphrases were sometimes taken for the original. ...Stoics ...sought to interpret him ...in accordance with their ...system. ...[T]hey were fond of "accommodating"... views... to their own..."

"Herakleitos looks down not only on the mass of men, but on all previous inquirers into nature."

"[H]e believed himself to have attained insight into... truth... not hitherto... recognised, though... staring men in the face (fr. 93). ...[W]e must ...find out what he was thinking ...when he launched into ...denunciations of human dulness and ignorance. The answer... in ...fragments, 18 and 45 ... the many apparently independent and conflicting things we know are really one, and ...this one is also many. The "strife of opposites" is really an "attunement" ...[[Wisdom|[W]isdom]] is not a knowledge of many things, but the perception of the underlying unity of the warring opposites."

"Philo... says: "For that which is made up of both the opposites is one; and, when the one is divided, the opposites are disclosed. Is not this... what the Greeks say their great and much belauded Herakleitos put in the forefront of his philosophy as summing it all up, and boasted of as a new discovery?""

"Anaximander had taught... the opposites were separated... from the Boundless, but passed away into it once more... paying the penalty for... unjust encroachments on one another. It is... implied... there is something wrong in the war of opposites, and... existence of the Many is a breach in the unity of the One. ...Herakleitos proclaimed ...there is no One without the Many, and no Many without the One. The world is at once one and many, and ...the "opposite tension" of the Many ...constitutes the unity of the One."

"[In] Plato.., the Sophist (242 d), the Eleatic stranger, after explaining how the maintained that what we call many is really one, proceeds:— But certain Ionian and (at a later date) certain Sicilian Muses remarked that it was safest to unite these two things, and to say that reality is both many and one, and is kept together by Hate and Love. "For," say the more severe Muses, "in its division it is always being brought together" (cf. fr. 59); while the softer Muses relaxed the requirement that this should always be so, and said that the All was alternately one and at peace through the power of Aphrodite, and many and at war with itself because of something they called Strife. ...the Ionian Muses stand ...for Herakleitos, and the Sicilian for Empedokles."

"[T]he differentiation of the one into many, and the integration of the many into one, are both eternal and simultaneous, and... this is the ground upon which... Herakleitos is contrasted with... Empedokles. ...[A]ccording to Plato, Herakleitos taught that reality was at once many and one."

"We must be careful... not to imagine that Herakleitos thus discovered... a logical principle. The identity in and through difference... was purely physical; logic did not yet exist, and... the principle of identity had not been formulated, it would have been impossible to protest against an abstract application of it."

"The identity ...as consisting in difference is simply that of the primary substance in all its manifestations."

"This identity had been realised... by the Milesians, but they... found a difficulty in the difference. Anaximander had treated the strife of opposites as an "injustice," and... Herakleitos set himself to show... it was the highest justice (fr, 62)."

"[T]his made it necessary for him to seek... a new primary substance... not merely... out of which the diversified world... might... be made, or from which opposites could be "separated out," but... which of its own nature would pass into everything else, while everything else would pass in turn into it. This he found in Fire..."

"The quantity of fire in a flame... appears to remain the same, the flame seems to be... a "thing"... yet the substance... is continually changing. ...[P]assing away in smoke ...its place ...always being taken by fresh ...fuel that feeds it. ...If we regard the world as an "ever-living fire" (fr. 20), we can understand ...it ...always becoming all things, while all things are always returning to it."

"This necessarily brings... a certain way of looking at the change and movement of the world. ...It follows that ...reality is like an ever-flowing stream ...nothing is ever at rest ...The substance of ...things ...is in constant change."

"This theory is usually summed up... "All things are flowing"... though... it cannot be proved that this is a quotation from Herakleitos."

"Plato... expresses the idea... clearly. "Nothing ever is, everything is becoming"; "All things are in motion like streams"; "All things are passing, and nothing abides"; "Herakleitos says somewhere that all things pass and naught abides; and, comparing things to the current of a river, he says that you cannot step twice into the same stream". (cf. fr. 41)—these are the terms in which he describes the system."

"Aristotle says the same... "All things are in motion," "nothing steadfastly is.""

"Herakleitos held..., that any... thing, however stable in appearance, was merely a section in the stream, and... the matter composing it was never the same in any two consecutive moments... [T]he idea was not... novel, and... hardly the central point in the system of Herakleitos."

"The Milesians held a similar view. The flux of Herakleitos was at most more unceasing and universal."

"In the fragments... we find nothing about rarefaction and condensation. The expression used is "exchange" (fr. 22)... a very good name for... when fire gives out smoke and takes in fuel..."

"[O]ur best account of the Theophrastean of Herakleitos is the fuller of the two accounts... in Laertios Diogenes... as follows:— ...He held that Fire was the element, and that all things were an exchange for fire, produced by condensation and rarefaction. But he explains nothing clearly. All things were produced in opposition, and all things were in flux like a river. The all is finite and the world is one. It arises from fire, and is consumed again by fire alternately through all eternity in... cycles. This happens according to fate. That which leads to the becoming of the opposites is called War and Strife; that which leads to the final conflagration is Concord and Peace. He called change the upward and the downward path, and held that the world comes into being in virtue of this. When fire is condensed it becomes moist, and when compressed it turns to water; water being congealed turns to earth, and this he calls the downward path. And, again, the earth is in turn liquefied, and from it water arises, and from that everything else; for he refers almost everything to the evaporation from the sea. This is the path upwards. R. P. 36 He held, too, that exhalations arose both from the sea and the land; some bright and pure, others dark. Fire was nourished by the bright ones, and moisture by the others. He does not make it clear what is the nature of that which surrounds the world. He held, however, that there were bowls in it with the concave sides turned towards us, in which the bright exhalations were collected and produced flames. These were the heavenly bodies. The flame of the sun was the brightest and warmest; for the other heavenly bodies were more distant from the earth; and for that reason gave less light and heat. The moon, on the other hand, was nearer the earth; but it moved through an impure region. The sun moved in a bright and unmixed region, and at the same time was at just the right distance from us. That is why it gives more heat and light. The eclipses of the sun and moon were due to the turning of the bowls upwards, while the monthly phases of the moon were produced by a gradual turning of its bowl. Day and night, months and seasons and years, rains and winds, and things like these, were due to the different exhalations. The bright exhalation, when ignited in the circle of the sun, produced day, and the preponderance of the opposite exhalations produced night. The increase of warmth proceeding from the bright exhalation produced summer, and the preponderance of moisture from the dark exhalation produced winter. He assigns the causes of other things in conformity with this. As to the earth, he makes no clear statement about its nature, any more than he does about that of the bowls. These, then, were his opinions. R. P. 39 b."

"How is it that, in spite of this constant flux, things appear relatively stable? ...[I]t is owing to the observance of the "measures," in virtue of which the aggregate bulk of each form of matter in the long run remains the same, though its substance is constantly changing, Certain "measures" of the "ever-living fire" are always being kindled, while like "measures" are always going out (fr. 20)..."

"Αll things are "exchanged" for fire and fire for all things (fr. 22), and this implies that for everything it takes, fire will give as much. “The sun will not exceed his measures” (fr. 29)."

"Herakleitos... explained the world by man rather than man by the world. ...Aristotle implies that soul is identical with the dry exhalation, and this is ...confirmed by the fragments. Man is made... of... fire, water, and earth. But, just as in the macrocosm fire is... the one wisdom, so in the microcosm... fire alone is conscious. When it has left the body..., the mere earth and water, is... worthless (fr. 85)."

"[T]he fire which animates man is subject to the "upward and downward path," just as much as the fire of the world. ..."All things are passing, both human and divine, upwards and downwards by exchanges.""

"We are just as much in perpetual flux as anything else in the world. We are and are not the same for two consecutive instants (fr. 81). The fire in us is perpetually becoming water, and the water earth; but, as the opposite process goes on simultaneously, we appear to remain the same."

"Man is subject to... in his "measures" of fire and water... [T]his gives rise to the alternations of sleeping and waking, life and death."

"The locus classicus on this... is... Sextus Empiricus, which reproduces the account of the Herakleitean psychology given by Ainesidemos... (R. P. 41):— The natural philosopher is of opinion that what surrounds us is rational and endowed with consciousness. According to Herakleitos, when we draw in this divine reason by... respiration, we become rational. In sleep we forget, but at our waking we become conscious once more. For in sleep... the mind... is cut off from... that which surrounds us, and only our connexion... by... respiration is preserved as a... root (from which the rest may spring again); and, when... thus separated, it loses the power of memory... When we awake again... it looks out through the openings of the senses, as if through windows, and coming together with the surrounding mind, it assumes the power of reason. Just... as embers... brought near the fire, change and become red-hot, and go out when they are taken away... so does the portion of... mind... become irrational when... cut off, and... become of like nature to the whole... through the greatest number of openings. In this passage there is... a... large admixture of later... ideas. In particular... identification of "that which surrounds us" with the air... for Herakleitos can have known nothing of air, which in his day was regarded as a form of water... The reference to the pores or openings of the senses is probably foreign... for the theory of pores is due to Alkmaion. ...[T]he distinction between mind and body is far too sharply drawn. ...[T]he important rôle assigned to respiration may very well be Herakleitean; for we ... met with it ...in Anaximenes. ...[T]he striking simile of the embers which glow when ...near the fire is genuine (cf. fr. 77)."

"The true Herakleitean doctrine doubtless was, that sleep was produced by the encroachment of moist, dark exhalations from the water in the body, which cause the fire to, burn low. In sleep, we lose contact with the fire in the world which is common to all, and retire to a world of our own (fr. 95). In a soul where the fire and water are evenly balanced, the equilibrium is restored in the morning by an equal advance of the bright exhalation."

"[I]n no soul are the fire and water... evenly balanced for long. One... acquires predominance, and the result... is death."

"It is death... to souls to become water (fr. 68); but that is... what happens to souls which seek after pleasure... a moistening of the soul (fr. 72), as... in... the drunken man, who... has moistened his soul to... an extent that he does not know where he is going (fr. 73). Even in gentle relaxation over our cups, it is... difficult to hide folly... (fr. 108)."

"That is why it is... necessary... to quench wantonness (fr. 103); for whatever our heart’s desire insists on it purchases at the price of life... [i.e.,] the fire within us (fr. 105)."

"The dry soul, that which has least moisture, is... best (fr. 74); but... preponderance of fire causes... a... different death... and wins "greater portions"... (fr. 101). ...[T]hose who fall in battle share their lot (fr. 102)."

"Those who die the fiery... death, become... gods... in a different sense from that in which the one Wisdom is god. It is probable that the corrupt fragment 123 refers to this unexpected fate (fr. 122)..."

"[A]s summer and winter are one, and... reproduce one another by their "opposite tension," so do life and death... and so... youth and age (fr. 78)."

"[T]he soul will be now living and now dead... it will only turn to fire or water... to recommence... its unceasing upward and downward path."

"The soul that has died from excess of moisture sinks down to earth; but from the earth comes water, and from water is once more exhaled a soul (fr. 68)."

"So, too... (fr. 67)... gods and men are... one. They live each others' life, and die each others' death. Those mortals that die the fiery death become immortal... [i.e.,] the guardians of the quick and the dead (fr. 123); and those immortals become mortal in their turn."

"Everything is... the death of something else (fr. 64)."

"The living and the dead are always changing places (fr. 78)... not only to the souls that have become water, but to those that have become fire and are now guardian spirits."

"[R]eal weariness is continuance in the same state (fr. 82), and... real rest, is change (fr. 83). Rest in any other sense is... dissolution (fr. 84). So they too are born once more."

"Plato’s contrast between Herakleitos and Empedokles ...is ...that, while Herakleitos said the One was always many, and the Many always one, Empedokles said the All was many and one by turns."

"[T]he absence of anything to show that Herakleitos spoke of a general ... becomes more patent when we turn to the few fragments which are supposed to prove it. The favourite is fr. 24, where... Fire was Want and Surfeit. [I]t has a perfectly intelligible meaning on our interpretation... confirmed by fr. 36. [I]t seems... artificial to understand the Surfeit as referring to the fact that fire has burnt everything else up, and... more so to interpret Want as meaning... fire... has turned into a world. The next is fr. 26 where... fire... will judge and convict all things. There is nothing... to suggest... fire will judge... at once rather than in turn, and... the advance of fire and water... we have seen... is... limited... These appear to be the only passages... the Stoics and the Christian apologists could discover, and... cannot bear the weight of their conclusion... [T]here was certainly nothing more definite to be found."

"It is much easier to find fragments which are on the face of them inconsistent with a general ."

"[W]hen anything becomes fire, something... equal... must cease to be fire, if the "exchange" is... just... and... we are assured by... the Erinyes (fr. 29)... that the sun does not take more than he gives. Of course there is... variation; but... strictly confined within limits, and is compensated in the long run by a variation in the other direction."

"[In] fr. 43... Herakleitos blames Homer for desiring the cessation of strife... The cessation of strife would mean that all things should take the upward or downward path... and cease to “run in opposite directions” If they all took the upward path, we should have a general conflagration."

"[I]n fr. 20 it is this world, and not merely the "ever-living fire," which is... eternal; and... its eternity depends upon... always kindling and always going out in the same "measures"... [i.e.,] encroachment in one direction is compensated by... encroachment in the other."

"[M]an, like the heavenly bodies, oscillates between fire and water; and that is... what Herakleitos taught."

"[N]either fire nor water can prevail completely... The whole process depends... on the fact that Surfeit is... Want... [i.e.,] an advance of fire increases the moist exhalation, while an advance of water deprives the fire of the power to cause evaporation. The conflagration... would destroy the opposite tension on which the rise of a new world depends, and... motion would become impossible."

"We know from Philo that Herakleitos supported his theory of the attainment of harmony through strife... There is... agreement between a passage of this kind in the pseudo-Aristotelian treatise... The Kosmos, and the Hippokratean work... [B]oth drew from... Herakleitos... made practically certain by the fact that this agreement extends... to the Letters of Herakleitos, which, though spurious, were... composed by some one who had access to the original work."

"The argument was that men... act just in the same way as Nature, and it is therefore surprising that they do not recognise the laws by which she works."

"The painter produces his harmonious effects by the contrast of colours, the musician by that of high and low notes. "If one were to make all things alike, there would be no delight in them." There are many similar examples in the Hippokratean tract, some... come from Herakleitos; but it is not easy to separate them..."

"[A] number of Herakleitean fragments... form a class by themselves, and are among the most striking... Their common characteristic... they assert... the identity of... things... usually regarded as opposites."

"Herakleitos meant to say, not that day was night or that night was day, but that they were two sides of the same process, namely, the oscillation of the "measures" of fire and water, and... neither would be possible without the other."

"Any explanation... of night will... be an explanation of day, and vice versa; for it will be an account of that which is common... manifests itself now as one and now as the other. ...[B]ecause it has manifested... in the one form... it must next appear in the other... [as] required by the law of compensation or Justice."

"This is only a particular application of the universal principle that the primary fire is one even in its division. It itself is, even in its unity, both surfeit and want, war and peace (fr. 36)."

"[T]he "satiety" which makes fire pass into other forms, which makes it seek "rest in change" (frs. 82, 83), and "hide itself" (fr. 10) in the "hidden attunement" of opposition, is only one side of the process. The other is the "want" which leads it to consume the bright vapour as fuel. The upward path is nothing without the downward (fr. 69). If either were to cease, the other would cease... and the world would disappear; for it takes both to make... stable reality."

"All other utterances of the kind are to be explained in the same way."

"If there were no cold, there would be no heat; for a thing can only grow warm if... it is already cold."

"[T]he same thing applies to the opposition of wet and dry (fr. 39)."

"These... are... the two primary oppositions of Anaximander, and Herakleitos is showing that the war... is really peace, for it is the common element in them (fr. 62) which appears as strife, and that... strife is justice, and not, as Anaximander had taught, an injustice... they commit one against the other, and which must be expiated by a reabsorption of both in their common ground."

"The strife itself is the common ground (fr. 62), and is eternal."

"The most startling of these sayings is that which affirms that good and evil are the same (fr. 57). This does not mean in the least... that good is evil or that evil is good, but... that they are the two inseparable halves of one and the same thing."

"A thing can become good only in so far as it is already evil, and evil only in so far as it is already good... everything depends on the contrast."

"Herakleitos is not a believer in absolute relativity. The process of the world is not merely a circle, but an "upward and downward path.""

"At the upper end, where the two paths meet, we have the pure fire, in which, as there is no separation, there is no relativity."

"[W]hile to man some things are evil and some things are good, all things are good to God (fr.61). ...[B]y God ...Herakleitos meant fire. He also calls it the "one wise," and perhaps said... it "knows all things." ...[H]e meant to say ...in it the opposition and relativity which are universal in the world disappear. ...[T]o this ...frs. 96, 97, and 98 refer."

"Herakleitos speaks of "wisdom" or the "wise" in two senses. ...[H]e said wisdom was "something apart from everything else" (fr. 18), meaning ...the perception of the unity of the many ...[H]e also applies the term to that unity... regarded as the "thought that directs the course of all things." This is synonymous with the pure fire which is not differentiated into two parts, one taking the upward and the other the downward path. That alone has wisdom; the partial things we see have not. We ourselves are only wise in so far as we are fiery (fr. 74)."

"With... reservations, Herakleitos was prepared to call the one Wisdom by the name of Zeus. Such... appears to be the meaning of fr. 65. It is not... to be pictured in the form of a man. In saying this, Herakleitos would only have been repeating... Anaximander and Xenophanes. He agrees further with Xenophanes in holding that this "god"... is one; but his polemic against popular religion was directed... against the rites and ceremonies... [rather] than their mere mythological outgrowth."

"He gives a list (fr. 124) of some of the most characteristic religious figures of his time, and... threatened them with the wrath to come."

"He comments upon the absurdity of praying to images (fr. 126), and... that blood-guiltiness can be washed out by the shedding of blood (fr. 130)."

"He seems also to have said that it was absurd to celebrate the worship of Dionysos by cheerful and licentious ceremonies, while was propitiated by gloomy rites (fr. 127). According to the mystic doctrine itself, the two were really one; and the one Wisdom ought to be worshipped in its integrity."

"The few fragments which deal with theology and religion hardly suggest to us that Herakleitos was in sympathy with the religious revival of the time, and yet we have been asked to consider his system "in the light of the idea of the mysteries.""

"The moral teaching of Herakleitos has sometimes been regarded as an anticipation of the "commonsense" theory of Ethics."

"The "common" upon which Herakleitos insists is... very different from common sense, for which... he had the greatest... contempt (fr. 111). It is... his strongest objection to "the many," that they live each in his own world (fr. 95), as if they had a private wisdom of their own (fr. 92); and public opinion is therefore... opposite of "the common.""

"The Ethics of Herakleitos are to be regarded as a corollary of his anthropological and cosmological views. Their chief requirement... keep our souls dry, and thus assimilate them to the one Wisdom... fire. That is what is... "common," and the greatest fault is to act like men asleep (fr. 94)... by letting our souls grow moist, to cut ourselves off from the fire in the world."

"The wise man would not try to secure good without its correlative evil. He would not seek for rest without exertion, nor expect to enjoy contentment without first suffering discontent. He would not complain that he had to take the bad with the good, but would consistently look at things as a whole."

"Herakleitos prepared the way for the Stoic world-state by comparing "the common" to the laws of a city. And these are... more than a type of the divine law: they are imperfect embodiments of it. They cannot... exhaust it altogether; for in all human affairs there is an element of relativity (fr. 91). "Man is a baby compared to God" (fr. 97). Such as they are, however, the city must fight for them as for its walls; and, if it has the good fortune to possess a citizen with a dry soul, he is worth ten thousand (fr. 113); for in him alone is "the common" embodied."

"We now come to the question of applying the observational tests to earlier theories. These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past. It now turns out that... all such theories are in conflict with observational requirements."

""Big Bang" theory"

"It is in the world of ideas and in the relation of his brain to the universe itself that the superiority of Man lies. The rise of Man may justly be described as an adventure in ideas."

"It has often been said that, if the human species fails to make a go of it here on the Earth, some other species will take over the running. In the sense of developing intelligence this is not correct. We have or soon will have, exhausted the necessary physical prerequisites so far as this planet is concerned. With coal gone, oil gone, high-grade metallic ores gone, no species however competent can make the long climb from primitive conditions to high-level technology. This is a one-shot affair. If we fail, this planetary system fails so far as intelligence is concerned."

"I do not believe that anything really worthwhile will come out of the exploration of the slag heap that constitutes the surface of the moon...Nobody should imagine that the enormous financial budget of NASA implies that astronomy is now well supported."

"We are inescapably the result of a long heritage of learning, adaptation, mutation and evolution, the product of a history which predates our birth as a biological species and stretches back over many thousand millennia... Going further back, we share a common ancestry with our fellow primates; and going still further back, we share a common ancestry with all other living creatures and plants down to the simplest microbe. The further back we go, the greater the difference from external appearances and behavior patterns which we observe today."

"Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards."

"Life cannot have had a random beginning … The trouble is that there are about two thousand enzymes, and the chance of obtaining them all in a random trial is only one part in 1040,000, an outrageously small probability that could not be faced even if the whole universe consisted of organic soup."

"Once we see, however, that the probability of life originating at random is so utterly minuscule as to make it absurd, it becomes sensible to think that the favorable properties of physics on which life depends are in every respect deliberate … . It is therefore almost inevitable that our own measure of intelligence must reflect … higher intelligences … even to the limit of God … such a theory is so obvious that one wonders why it is not widely accepted as being self-evident. The reasons are psychological rather than scientific."

"The chance that higher life forms might have emerged in this way is comparable with the chance that a tornado sweeping through a junk-yard might assemble a Boeing 747 from the materials therein."

"The notion that not only the biopolymer but the operating program of a living cell could be arrived at by chance in a primordial organic soup here on the Earth is evidently nonsense of a high order."

"A junkyard contains all the bits and pieces of a Boeing 747, dismembered and in disarray. A whirlwind happens to blow through the yard. What is the chance that after its passage a fully assembled 747, ready to fly, will be found standing there? So small as to be negligible, even if a tornado were to blow through enough junkyards to fill the whole Universe."

"Between the ages of five and nine I was almost perpetually at war with the educational system. ...As soon as I learned from my mother that there was there was a place called school that I must attend willy-nilly—a place where you were obliged to think about matters prescribed by a 'teacher,' not about matters decided by yourself—I was appalled."

"The creationist is a sham religious person who, curiously, has no true sense of religion. In the language of religion, it is the facts we observe in the world around us that must be seen to constitute the words of God. Documents, whether the Bible, Qur'an or those writings that held such force for Velikovsky, are only the words of men. To prefer the words of men to those of God is what one can mean by blasphemy. This, we think, is the instinctive point of view of most scientists who, curiously again, have a deeper understanding of the real nature of religion than have the many who delude themselves into a frenzied belief in the words, often the meaningless words, of men. Indeed, the lesser the meaning, the greater the frenzy, in something like inverse proportion."

"To achieve anything really worthwhile in research it is necessary to go against the opinions of one's fellows. To do so successfully, not merely becoming a crackpot, requires fine judgement, especially on long-term issues that cannot be settled quickly. ...To hold popular opinion is cheap, costing nothing in reputation, whereas to accept that there is evidence pointing oppositely... is to risk scientific tar and feathers. Yet not to take the risk is to make certain that, if something new is really there, you won't be the one to find it."

"When I was young, the old regarded me as an outrageous young fellow, and now that I'm old the young regard me as an outrageous old fellow."

"There is a coherent plan to the universe, though I don't know what it's a plan for."

"I do not see any sense in continuing to skirmish on a battlefield where I can never hope to win. The Cambridge system is effectively designed to prevent one ever establishing a directed policy — key decisions can be upset by ill-informed and politically motivated committees. To be effective in this system one must for ever be watching one's colleagues, almost like a Robespierre spy system. If one does so, then of course little time is left for any real science."

"Once a photograph of the Earth, taken from outside, is available, we shall, in an emotional sense, acquire an additional dimension... Once let the sheer isolation of the Earth become plain to every man, whatever his nationality or creed, and a new idea as powerful as any in history will be let loose. (1948)"

"Once the spark was struck the story would spread like wildfire, and would be in the papers in next to no time. The Director had never had any cause to think highly of newspaper reporters, particularly of their scientific accuracy."

"“But I can’t go along and gatecrash.” “Nonsense, of course you can come—a guest from England! You’ll be the lion of the party. Probably half a dozen film moguls from Hollywood will want to sign you up on the spot.” “All the more reason for not going,” said Kingsley."

"The two men were mentally too dissimilar for more than a half hour of conversation between them to be possible."

"“I’m still waiting to hear how I should have compromised. Are you sure that ‘compromise’ and ‘capitulate’ are not synonymous in your vocabulary?”"

"Ifs and buts are the stuff of politics, Mr. Parkinson. As a scientist I am concerned with facts not with motives, suspicions, and airy-fairy nothingness."

"“You haven’t very much respect for my profession, have you, Professor Kingsley?” “Since it is you who wish for frankness, I will tell you that I have not. I regard politicians rather as I regard the instruments on the dashboard of my car. They tell me what is going on in the engine of state, but they don’t control it.”"

"“Not everyone views the government with quite the same disrespect that you do.” “No, more’s the pity.”"

"The policy was to keep everything in watertight compartments. In the interests of security, they said, but more likely in the interests of inefficiency."

"Before anyone starts criticising, let me say that I know it’s a preposterous idea and I wouldn’t suggest it for a moment if the alternative weren’t even more outrageously preposterous."

"I will say this for you, Chris. I never knew anyone who was better at finding work for other people."

"Viewed from a wholly logical point of view the bearing and rearing of children is a thoroughly unattractive proposition. To a woman it means pain and endless worry. To a man it means extra work extending over many years to support his family. So, if we were wholly logical about sex, we should probably not bother to reproduce at all. Nature takes care of this by making us utterly and wholly irrational."

"It isn’t the Universe that’s following our logic, it’s we that are constructed in accordance with the logic of the Universe. And that gives what I might call a definition of intelligent life: something that reflects the basic structure of the Universe."

"“Now do you see my point?” “I’m beginning to see through a glass darkly. You mean that the mental make-up of a leading politician is likely to be such that he couldn’t dream it possible that anyone could find the prospect of becoming a dictator wholly unpalatable.” “Yes, I can see it all, Chris,” Leicester grinned. “Graft everywhere, executions just for the laughs, no wife or daughter safe.”"

"Losing power, utterly and completely, is the most dreadful prospect that a politician can think of. It overshadows everything else."

"It’s only too easy to read your own state of mind into what other people say."

"Lives loss through an ‘act of God’ are regretted, perhaps deeply regretted, but they do not arouse our wildest passions. It is otherwise with lives that are forfeited through deliberate human agency. The word ‘deliberate’ is important here. One deliberate murder can produce a sharper reaction than ten thousand deaths on the roads."

"“By and large, conventional religion, as many humans accept it, is illogical in its attempt to conceive of entities lying outside the Universe. Since the Universe comprises everything, it is evident that nothing can lie outside it. The idea of a ‘god’ creating the Universe is a mechanistic absurdity clearly derived from the making of machines by men. I take it that we are in agreement about all this.”"

"It is easy to give a recipe for writing a successful non-fiction book—simply find grounds for optimism that no one has spotted before and expatiate thereon."

"Inevitably we are led to ask: why does this appalling rubbish get published—and not merely published, but displayed prominently in the very heart of an apparently respectable newspaper? In a word, because this is what people want, and if The Times didn’t fill itself pretty well from cover to cover with such stuff it would soon go out of business."

"This may seem like insanity, and so it is. It offsets the real problems of modern life. How can an apparently insane species manage to organize itself in a civilized way? I am not so sure that it can. The big mystery is why we have managed to get so far."

"Any organization is better than no organization. Tribal customs show great variety, but they have in common the property of enabling a number of humans to act in concert with each other. It is the communal character of group action that is important, not the particular customs of any particular tribe. Group action is the essential common denominator of all tribal life. And any group acting together is far more powerful than the same number of persons acting only as individuals."

"I have been astonished by the way in which the tug of war between left and right is conducted. What seems to happen is this: the left, the ideas-men, the liberals, propose a new idea involving change. The conservatives oppose all change on principle. An argument now develops in which I find myself unable to take any real part. I know that without new ideas, without change, even the most modest enterprise soon congeals and dies. But I also know that most new ideas, like mutations, turn out very badly. Hence from the beginning I am aware of the basic dilemma. But not so the liberals or the conservatives. The liberals, for their part, are quite convinced that the new idea is an excellent one, but when pressed for proof they merely follow the dictum of Robert Owen, “never argue, repeat your assertion.” So far as the liberals are concerned I feel as if I were in the presence of divine revelation. The conservatives on the other hand are blockers, stone wallers, Verdun-types with “they shall not pass” expression written all over their faces. On the whole, because I know that most new ideas are dubious, I end by voting with the conservatives."

"The attitude of the conservative is basically wrong: change should not be opposed. Not in a root and branch sense. What the conservatives should demand and insist on is that any projected changes should be reversible. The deadly changes are those which are irreversible, like the British introducing Greeks into Cyprus. Or like taking the sparrow and the rabbit to Australia. So long as a projected change can be shown to be reversible there should be no very serious objection to making a tryout. If the first step along the new road turns out well, the second step can be made, but if it turns out badly one simply retreats to where one was before. This seems to me to be the essential principle of social change."

"So far from proceeding in this way, the really curious feature of every organization in which it has been my misfortune to be involved is that while people argue vociferously and almost completely without data about all projected changes they show a little or no interest in the effects of changes after they have been introduced."

"All people are the same, pretty well irrespective of color, creed, or the way they happen to grunt out their language."

"Where, then, do we go from here? The answer to this critical question plainly depends on whether the rise of the world population becomes permanently stabilized or not. Will the warnings of the past be heeded? My suspicion is that they will not."

"However, there is one respect in which the human species has shown not the slightest originality—its excessive reproductive vigor."

"There may be hagglers who will dispute this statement, but if so I propose to disregard them."

"The concept here is that a highly organized society can collapse through a population overload, even though the people themselves are not starving. It is the organization that ultimately becomes overloaded and collapses."

"Experience shows that knowledge dies very hard once it has been obtained—the acquisition of knowledge is essentially irreversible, a truth already recognized in the Garden of Eden."

"I am often asked what it is like to be a scientist and how one goes about being a scientist. I find such questions uncomfortable because I know of no nicely potted answers to them. It is necessary to dig deep into one’s own experience to produce anything like a worthwhile assessment. And this is to risk the perils of autobiography, usually so fascinating to the narrator and so boring to the reader."

"Quite recently I was asked to write an article to be entitled, “How to Become a Good Scientist.” In communicating my refusal to the periodical in question I was tempted to end the argument in one sentence, “By not writing articles such as this,” and then demanding my fee."

"My cast of mind is a very bad handicap in this age of the committee. My true thoughts when I sit on a committee are so grotesquely at variance with the business in hand that they simply cannot be expressed at all. I am overwhelmed by the fatuity of most of what is being said, and there is a constant parade in my mind of the pathetic political figures of the first third of the present century."

"All people are pretty much alike, except in so far as ambition may change a man from a normal person into a machine or a monster."

"I helped him willingly and most efficiently, the latter because I knew that if I did jobs cheerfully and badly I wouldn’t be asked too often."

"His new leisure also afforded my father the opportunity of indulging another of his favorite occupations—talking. There was a great deal of talk in our house, which had two effects on me: one, that I learned not to listen when I don’t want to listen; and the other, an aversion to talking."

"There is no substitute for continuous endeavor. Of course all older men have good intentions, they have every wish “to keep up.” But the endless calls of students and committees and the ceaseless ringing of the telephone can defeat the best intentions. Only very recently I myself summoned the courage to deal with the problem. My solution is to answer only essential letters, entirely to ignore the telephone, and to restrict severely my participation in committee meetings. In modern ant-like society, with its penchant for excreting mountains of trivial literature, it needs an enormous determination to follow these simple precepts."

"There is no room in these streamlined days for such artistry. Everything is now decided by rule and rote, but this is one of the reasons why England is no longer in the great country she used to be."

"My education was still full of holes, which I made a resolve to fill. I am still trying to carry it out."

"Of all the backgrounds it seems to me that the typical suburban community must be by far the worst. The child’s parents have already compromised with life by living in such a place. It would be far better from the child’s point of view to be raised in an actual slum. The danger is, of course, that the child quickly comes to regard comfort as the number one priority."

"Assuming children and students do not wish to learn anything, then I suppose the present method of teaching is about right. It seems predicated on the notion that learning is an unpleasant medicine which must be swallowed at any price. But where a child is keen to learn, present methods seem woefully and even shockingly inadequate."

"The correct procedure I am sure it is to learn by doing, not by being told what to do. The notion that one can learn by attending a course of lectures is as absurd as the notion that the way to learn to ride a bicycle would be to hire someone to ride it for you, and to sit hour after hour watching him. The only reason for attending a lecture is to acquire hints as to the right method of tackling some particular problem or other. And this would be almost unnecessary in a properly designed and graded system of examples."

"But only gradually have I learned that such ultimate successes are not what the present-day authorities in Britain really want. What really delights them is extreme tidiness combined with a façade of everyday competence. This of course is why Britain plunges further and further downhill with every passing year. The truth is the opposite: it is the ultimate success that really counts."

"There is an important difference between an advance in science and achievements in the humanities. A great musician consumes intellectual capital, he does not supply it, or at least it is usual for him to consume more than he creates. It has been impossible to use the motto theme of the Fifth Symphony after Beethoven used it. In science, on the other hand, the situation is the other way round. A breakthrough invariably opens up more new problems to be solved. A Newton or an Einstein may leave the world with a century or more of clearing up to be done."

"One could conceive of other abstract systems, the consequences of which could be calculated, without it being necessary to provide a realization in actual material terms. We can conceive of other universes without those universes being compelled to exist. This indeed is the business of the pure mathematician."

"God was very much disappointed, and wanted first to contract the universe again, and to start all over from the beginning. But it would be much too simple. Thus being almighty, God decided to correct His mistake in a most impossible way. And God said: "Let there be Hoyle." And there was Hoyle. And God looked at Hoyle … and told him to make heavy elements in any way he pleased. And Hoyle decided to make heavy elements in stars, and to spread them around by supernovae explosions."

"Hoyle's enduring insights into stars, nucleosynthesis, and the large-scale universe rank among the greatest achievements of 20th-century astrophysics. Moreover, his theories were unfailingly stimulating, even when they proved transient."

"In the popular mind, if Hoyle is remembered it is as the prime mover of the discredited Steady State theory of the universe. "Everybody knows" that the rival Big Bang theory won the battle of the cosmologies, but few (not even astronomers) appreciate that the mathematical formalism of the now-favoured version of Big Bang, called inflation, is identical to Hoyle's version of the Steady State model."

"Not far from the meeting's venue, at one of the famed Observatory Club tea meetings, Fred once started a talk by saying, 'Oh, Ooh, basically a star is a pretty simple thing.' And from the back of the room was heard the voice of R. O. Redman, saying, 'Well, Fred, you'd look pretty simple too, from ten parsecs!'"

"It was a bank holiday, and Mr Tompkins, the little clerk of a big city bank, slept late and had a leisurely breakfast. Trying to plan his day, he first thought about going to some afternoon movie and, opening the morning paper, turned to the entertainment page. But none of the films looked attractive to him. He detested all this Hollywood stuff, with infinite romances between popular stars. If only there were at least one film with some real adventure, something unusual and maybe even fantastic about it. But there was none. Unexpectedly, his eye fell on a little notice in the corner of the page. The local university was announcing a series of lectures on the problems of modern physics, and this afternoon's lecture was to be about Einstein's Theory of Relativity. Well, that might be something!"

"There was a young fellow from Trinity, Who took the square root of infinity. But the number of digits, Gave him the fidgets; He dropped Math and took up Divinity."

"It is well known that theoretical physicists cannot handle experimental equipment; it breaks whenever they touch it. Pauli was such a good theoretical physicist that something usually broke in the lab whenever he merely stepped across the threshold. A mysterious event that did not seem at first to be connected with Pauli's presence once occurred in Professor J. Franck's laboratory in Göttingen. Early one afternoon, without apparent cause, a complicated apparatus for the study of atomic phenomena collapsed. Franck wrote humorously about this to Pauli at his Zürich address and, after some delay, received an answer in an envelope with a Danish stamp. Pauli wrote that he had gone to visit Bohr and at the time of the mishap in Franck's laboratory his train was stopped for a few minutes at the Göttingen railroad station. You may believe this anecdote or not, but there are many other observations concerning the reality of the Pauli Effect!"

"With very few exceptions, philosophers do not know much science and do not understand it, which is quite natural because science lies beyond the boundaries of typical philosophical subjects such as ethics, aestetics, and gnosiology. But while in the free countries philosophers are quite harmless, in the dictatorial countries they constitute a great danger for the development of science. In Russia, state philosophers are bred in the Communist Academy in Moscow and are placed in all the educational and research institutions to prevent the professors and researchers from falling into idealistic, capitalistic heresies. The state philosophers are usually familiar with the subject of the research institution they are going to supervise, being either former schoolteachers or having taken in the academy a one-semester course on the subject in question. But they rank in the their power above the scientific directors of the institution and can veto any research project on publication which deviates from the correct ideology. One notable example of philosophical dictatorship in Russian science was the prohibition of Einstein's theory of relativity on the ground that it denied world ether, "the existence of which follows directly from the philosophy of dialectical materialism". It is interesting to note that the existence of the "world ether" was doubted long before Einstein by Engels, who in one of his letter to friend wrote "...the world ether, if it exists"."

"I decided to get Ph.D. in experimental physics because experimental physicists have their own room in the Institute where they can hang their coat, whereas theoretical physicists have to hang their coat at the entrance."

"I feel that matter has properties which physics tells you."

"So I am just sitting and waiting, listening, and if something exciting comes, I just jump in."

"If the expansion of the space of the universe is uniform in all directions, an observer located in anyone of the galaxies will see all other galaxies running away from him at velocities proportional to their distances from the observer."

"It took less than an hour to make the atoms, a few hundred million years to make the stars and planets, but five billion years to make man!"

"The physicist George Gamow was also an entertaining popularizer. He once told the story of how with his wife and their baby daughter he visited the Leaning Tower of Pisa. As they climbed the steps, they noticed an increasingly musty smell, which they first attributed to the ancient walls of the building. Then, however, they began to suspect their little girl, and by the time they reached the top it was clear that she needed immediate attention. “And from the very place,” explained Gamow, raising his arm and his voice dramatically, “where Galileo launched his experimental objects, we also propelled…”"

"Rutherford did not pretend to understand quantum mechanics, but he understood that the Gamow formula would give his accelerator a crucial advantage. Even particles accelerated at much lower energies... would be able to penetrate into nuclei. Rutherford invited Gamow to Cambridge in January 1929... [They] became firm friends and Gamow's insight gave Rutherford the impetus to go full steam ahead with the building of his accelerator."

"Take a look at George Gamow, who is now recognized as one of the great cosmologists of the last hundred years. I speculate that he probably didn't win the Nobel Prize because people could not take him seriously. He wrote children's books. His colleagues have publicly stated his writing children's books on science had an adverse effect on his scientific reputation, and people could not take him seriously when he and his colleagues proposed that there should be a cosmic background radiation, which we now know to be one of the greatest discoveries of 20th-century physics."

"Gamow was rather childlike, always wanting to play, and introducing a sort of light humor into all occasions. He was very fond of drawing pictures of Mickey Mouse. He added a lot to the entertainment that we had. He had some good ideas, applications which led to important developments in quantum theory, but I do not think he did any work which was very deep."

"If contribution in life is measured by the influence of a person's best ideas, then George Gamow's contribution has been immense. He explained radioactive decay, described reaction mechanisms and rates in the interior of stars, proposed how the elements were made, and suggested how DNA might provide the code for protein synthesis. Those topics have evolved into major fields of science..."

"Es Gamow't wieder"

"Gamow was fantastic in his ideas. He was right, he was wrong. More often wrong than right. Always interesting; … and when his idea was not wrong it was not only right, it was new."

"By an incredible coincidence, Gamow and Edward Condon, who had discovered simultaneously and independently the explanation of radioactivity (one in Russia, the other in this country), came to spend the last ten years of their lives within a hundred yards of each other in Boulder."

"The Big Bang theory says nothing about what banged, why it banged, or what happened before it banged."

"It is said that there’s no such thing as a free lunch. But the universe is the ultimate free lunch."

"The recent developments in cosmology strongly suggest that the universe may be the ultimate free lunch."

"It becomes very tempting to ask whether, in principle, it's possible to create a universe in the laboratory—or a universe in your backyard—by man-made processes."

"It turns out that the energy of a gravitational field—any gravitational field—is negative. During inflation, as the universe gets bigger and bigger and more and more matter is created, the total energy of matter goes upward by an enormous amount. Meanwhile, however, the energy of gravity becomes more and more negative. The negative gravitational energy cancels the energy in matter, so the total energy of the system remains whatever it was when inflation started—presumably something very small. ...This capability for producing matter in the universe is one crucial difference between the inflationary model and the previous model."

"We should not act like we know that the universe began with the Big Bang... we'll see that there are strong suggestions that the Big Bang was perhaps not really the beginning of existence, but really just the beginning of our local universe, often called a pocket universe."

"What the Big Bang theory tells us, is that at least our region of the universe 13.82 billion years ago, was an extremely hot, dense uniform soup of particles which in the conventional standard Big Bang model filled literally all of space—and now we certainly believe that it filled essentially all of the space that we have access to—uniformly. ...This is contrary to a popular cartoon image of the Big Bang, which is just plain wrong. The cartoon image of the Big Bang is the image of a small egg of highly dense matter that then exploded and spewed out into empty space. That is not the scientific picture of the Big Bang. ...If there was a small egg that exploded into empty space, you would certainly expect that today you would see something different if you were looking towards where the egg was, versus looking the opposite direction, but we don't see any effect like that. When we look around the sky the universe looks completely uniform, on average, in all directions, to a very high degree of accuracy... So we don't see a sign of an egg having happened anywhere. Rather, the Big Bang seems to have happened everywhere, uniformly."

"The conventional Big Bang theory does not say anything about what caused the expansion. It really is only a theory about the aftermath of a bang. In the scientific version of the Big Bang, the universe starts with everything already expanding, with no explanation of how that expansion started... So the Scientific version of the Big Bang theory is not really a theory of a bang, it's really a theory of the aftermath of a bang."

"The conventional Big Bang theory says nothing about where all the matter came from. The theory really assumes that for every particle that we see in the universe today, there was, at the very beginning, at least some precursor particle, if not the same particle, with no explanation of where all those particles came from."

"In short what I like to say is that the Big Bang says nothing about what banged, why it banged, or what happened before it banged. It really has no bang in the Big Bang. It is a bangless theory, despite its name."

"Inflation is a prequel to the conventional Big Bang theory. ...It does provide a theory of the propulsion that drove the universe into this humungous episode of expansion which we call the Big Bang."

"The miracle of physics that I'm talking about here is something that was actually known since the time of Einstein's general relativity; that gravity is not always attractive. Gravity can act repulsively. Einstein introduced this in 1916... in the form of the cosmological constant, and the original motivation of modifying the equations of general relativity to allow this was because Einstein thought that the universe was static, and he realized that ordinary gravity would cause the universe to collapse if it was static. ...The fact that general relativity can support this gravitational repulsion, still being consistent with all the principles that general relativity incorporates, is the important thing which Einstein himself did discover.."

"Inflation takes advantage of this possibility... to let gravity be the repulsive force that drove the universe into the period of expansion that we call the Big Bang. In fact, when one combines general relativity with conventional ideas, now, in particle physics there really is a pretty clear indication, I should say, not quite a prediction... that at very high energy densities one expects to find states of matter which literally turn gravity on its head and cause gravity to become repulsive."

"What it takes to produce a gravitational repulsion is a negative pressure. According to general relativity, it turns out... both pressures and energy densities can produce gravitational fields, unlike Newtonian physics, where it's only mass densities that produce gravitational fields."

"A positive pressure produces an attractive gravitational field... Positive pressures are just sort of normal pressures and attractive gravity is normal gravity, so normal pressures produce normal gravity, but it is possible to have negative pressures, and negative pressures produce repulsive gravity, and that's the secret of what makes inflation possible."

"A very plausible choice for when inflation might have happened would be when the energy scales of the universe were at the scale of grand unified theories... which unify the weak, strong and electromagnetic interactions into a single unified interaction. ..we're talking about energies which are about 1016 times the equivalent energy of a proton mass. ...the initial patch would only have to be the ridiculously small size of about 10-28 cm across to be able to lead ultimately to the creation of everything that we see on the vast scale of which we see it."

"The gravitational repulsion created by this small patch of repulsive gravity material would be, then, the driving force of the Big Bang and it would cause the region to undergo exponential expansion... there is a certain doubling time, and if you wait the same amount of time it doubles again, and if you wait the same amount of time it doubles again... and it's because these doublings build up so dramatically, it doesn't take very much time to build the whole universe. In about 100 doublings this tiny patch of 10-28 cm can become large enough, not to be the universe, but to be a small marble-sized region which will then ultimately become the observed universe, as it continues to coast outward after inflation ends."

"The discovery of the CMB cemented the notion of a big bang. But for all its elegance, the theory had thrown up some intractable problems. Soon after the CMB was discovered, Dicke went to Cornell to talk about... the flatness problem. ...the universe seemed to be flat, meaning that the ratio of actual matter density to the critical density... Omega, was very close to 1. And for today's universe to have Omega anywhere near 1, its value just one second after the big bang had to be exactly 1 to a precision of about fourteen decimal places. Nothing in the laws of physics suggested why... In Dicke's audience was a young postdoc named Alan Guth. He was a particle physicist who had no interest in cosmology. But something about the talk tickled his fancy and set him on a journey that would solve the big-bang theory's most frustrating problem."

"Most of what we know, or believe we know, about the early moments of the universe is thanks to an idea called inflation theory first propounded in 1979 by a junior particle physicist, then at Stanford, now at MIT, named Alan Guth. He was thirty-two years old and, by his own admission, had never done anything much before. He would probably never have had his great theory except that he happened to attend a lecture on the Big Bang given by none other than Robert Dicke. The lecture inspired Guth to take an interest in cosmology, and in particular in the birth of the universe."

"We now address two of the drawbacks [of the standard Big Bang theory]... the flatness problem and the horizon problem. In the early 1980's, Alan Guth resolved these two problems with his inflationary theory. His basic idea was that the universe enters a false vacuum state shortly after the Big Bang, then tunnels out and expands exponentially. We choose to discuss Guth's original model (now called classical model or old inflation) for pedagogic reasons. Guth's model has many nice qualitative features; it does not work quantitatively. Therefore, A. Linde, A. Albrecht, P. Steinhardt, and others constructed new models as remedies. It is not clear which of the new models is correct..."

"According to Guth, he had discovered the equations of De Sitter's cosmology (1917), written in the form introduced somewhat later by Georges Lemaitre (1925), as part of his MIT Thesis, before introducing inflation as the starting point of his new cosmology. After taking care, by means of inflation of the "monopole problem". ...Guth went one step further to solve the so called "flatness problem". ...Guth finally goes on to explain how his theory of inflation solves the "horizon problem". ...we will analyze in some detail to what extent the "monopole problem", the "flatness problem" and the "horizon problem" require, or not, cosmic inflation as a problem solving "paradigm"."

"Prior to the downfall of the GUT in the mid 1980s, Alan Guth, an elementary particle theorist, was trying to explain the scarcity of the magnetic monopoles in the universe. The standard cosmological model predicted that there should be as many monopoles as there are nucleons! Since all attempts at finding a monopole had failed, Guth suggested that the universe must have had an inflation phase during which it expanded exponentially. This exponential growth was so rapid that it diluted any existing monopoles so much so that today there may be only a few in our observable universe."

"One of the issues with the then generally accepted theory of the Big Bang was the uniformity of temperature measured in any direction out in the universe, no explosion on Earth could occur as uniformly. In the early 1980's Alan Guth postulated that the universe initially grew from a small enough volume, a fraction of the size of an atom, for temperature to have equalized, within its first billionth of a second of age, to then expand exponentially..."

"It was fortunate that Alan Guth did his work at the same time that another idea came into fashion, which was the theory that we could understand why the universe contains matter and not antimatter in terms of some asymmetry, some favoritism for matter over antimatter in the early universe; it's no good having a scheme that can inflate the universe to enormous dimension of it's not possible to create matter to fill that large universe."

"A just city should favor justice and the just, hate tyranny and injustice, and give them both their just desserts."

"Farabi followed Plato not merely as regards the manner in which he presented the philosophic teaching in his most important books. He held the view that Plato’s philosophy was the true philosophy. To reconcile his Platonism with his adherence to Aristotle, he could take three more or less different ways. First, he could try to show that the explicit teachings of both philosophers can be reconciled with each other. He devoted to work is partly based on the so-called Theology of Aristotle: by accepting this piece of neo-platonic origin as a genuine work of Aristotle, he could easily succeed in proving the substantial agreement of the explicit teachings of both philosophers concerning the crucial subjects. It is however very doubtful whether Farabi considered his Concordance as more than an exoteric treatise, and thus whether it would be wise of us to attach great importance to its explicit argument. Secondly, he could show that the esoteric teachings of both philosophers are identical. Thirdly, he could show that “the aim” of both philosophers is identical."

"I think the weird thing about being a scientist, or an academic in general, is you have to believe really strongly in what you do, while questioning it all the time ... and that's a hard balance to have."

"The universe has its secrets. Extra dimensions of space might be one of them. If so, the universe has been hiding those dimensions, protecting them, keeping them coyly under wraps. From a casual glance, you would think that the cheese man ate cheese but you wrong."

"When it comes to the world around us, is there any choice but to explore?"

"Physics has entered a remarkable era. Ideas that were once the realm of science fiction are now entering our theoretical — and maybe even experimental — grasp. Brand-new theoretical discoveries about extra dimensions have irreversibly changed how particle physicists, astrophysicists, and cosmologists now think about the world. The sheer number and pace of discoveries tells us that we've most likely only scratched the surface of the wondrous possibilities that lie in store. Ideas have taken on a life of their own."

"We certainly don't yet know all the answers. But the universe is about to be pried open."

"Secrets of the cosmos will begin to unravel. I, for one, can't wait."

"When I was in school I liked math because all the problems had answers. Everything else seemed very subjective."

"Sometimes I have a sense of what I'm seeing being a small fraction of what's there. Not always there, but probably more often than I realize. Something will come up, and I'll realize I'm thinking about the world a little differently than my friends."

"In the history of physics, every time we've looked beyond the scales and energies we were familiar with, we've found things that we wouldn't have thought were there. You look inside the atom and eventually you discover quarks. Who would have thought that? It's hubris to think that the way we see things is everything there is."

"If we don't do it now, we'll probably never do it. We've built up the technology; we're at a point where if we don't continue, we'll lose that expertise, and we'll have to start all over again. True, it's expensive, but at the end of the day I believe it will be worth it. It makes a difference in terms of who we are, what we think, how we view the world. These are the kinds of things that get people excited about science, so you have a more educated public."

"Science is not religion. We're not going to be able to answer the "why" questions. But when you put together all of what we know about the universe, it fits together amazingly well."

"Religion asks questions about morals, whereas science just asks questions about the natural world. But when people try to use religion to address the natural world, science pushes back on it, and religion has to accommodate the results. Beliefs can be permanent, but beliefs can also be flexible. Personally, if I find out my belief is wrong, I change my mind. I think that's a good way to live."

"Faith just doesn't have anything to do with what I'm doing as a scientist. It's nice if you can believe in God, because then you see more of a purpose in things. Even if you don't, though, it doesn't mean that there's no purpose. It doesn't mean that there's no goodness. I think that there's a virtue in being good in and of itself. I think that one can work with the world we have."

"I think it's a problem that people are considered immoral if they're not religious. That's just not true. This might earn me some enemies, but in some ways they may be even more moral. If you do something for a religious reason, you do it because you'll be rewarded in an afterlife or in this world. That's not quite as good as something you do for purely generous reasons."

"And indeed, if VSL is correct, black holes may have very different properties than we thought. Collapsing stars could have a totally different demise and die a rather eccentric death."

"The game of science can accurately be described as a never-ending insult to human intelligence."

"It was then that through the open door Einstein saw the man connecting the new battery, and precisely at the same time he did it, Einstein saw the cows jumping up away from the wire. All at once. Exactly. A fair amount of displeased mooing ensued."

"In that year [Einstein] had roughly equal numbers of large and small cats. Therefore, quite logically, he cut two holes in each door: a large one for the large cats, and a small one for the small cats. It made perfect sense. ... A hole should have a meaningful existence, and the small cats might be offended if a personalized nothing was not prepared for them."

"Thus, the distance between any two galaxies increases in time, creating the illusion of mechanical motion. But in reality, galaxies just sit there, contemplating the spectacle of the universe creating more and more space in between them."

"I've always felt that copious use of the word 'something' allows anyone to solve any problem, even insoluble ones."

"For instance, the blood of hibernating arctic squirrels may supercool to minus 3 degrees, when it would normally congeal. The supercooled blood still flows, since it remains a liquid, but the slightest disturbance will cause it to freeze, killing the squirrel; therefore, you should not disturb hibernating arctic squirrels."

"Inflation is really like drugging the baby universe with speed. The supercool union of the hitherto unfriendly gods was blessed by amphetamine, and this made the universe inflate rather than just expand. The early orgy of expansion in the universe comes to an abrupt end as soon as the supercooled particle stuff finally freezes."

"Ever since then, the place has accommodated people with the necessary level of imbalance required to come up with new ideas."

"Although the term dialogue was really a euphemism for scientists trying to kill each other, this format worked very well..."

"Cornelia would not be altogether surprised if she saw the grazing cow start tap dancing, lap dancing, or whatever quantum gravity might cause cows to do."

"My goal is to show that the heavenly machine is not a kind of divine living being but similar to a clockwork insofar as all the manifold motions are taken care of by one single absolutely simple magnetic bodily force, as in a clockwork all motion is taken care of by a simple weight. And indeed I also show how this physical representation can be presented by calculation and geometrically."

"Nature uses as little as possible of anything."

"The die is cast; I have written my book; it will be read either in the present age or by posterity, it matters not which; it may well await a reader, since God has waited six thousand years for an interpreter of his words."

"We do not ask for what useful purpose the birds do sing, for song is their pleasure since they were created for singing. Similarly, we ought not to ask why the human mind troubles to fathom the secrets of the heavens. The diversity of the phenomena of nature is so great and the treasures hidden in the heavens so rich precisely in order that the human mind shall never be lacking in fresh nourishment."

"In Terra inest virtus, quae Lunam del."

"There is a force in the earth which causes the moon to move."

"I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses."

"I used to measure the heavens, now I measure the shadows of Earth. Although my mind was heaven-bound, the shadow of my body lies here."

"Temporis filia veritas; cui me obstetricari non pudet."

"Truth is the daughter of time, and I feel no shame in being her midwife."

"The earth is the sphere, the measure of all; round it describe a dodecahedron; the sphere including this will be Mars. Round Mars describe a tetrahedron; the sphere including this will be Jupiter. Describe a cube round Jupiter; the sphere including this will be Saturn. Now, inscribe in the earth an icosahedron, the sphere inscribed in it will be Venus: inscribe an octahedron in Venus: the circle inscribed in it will be Mercury."

"Either... the moving intelligences of the planets are weakest in those that are farthest from the sun, or... there is one moving intelligence in the sun, the common center, forcing them all round, but those most violently which are nearest, and that it languishes in some sort and grows weaker at the most distant, because of the remoteness and the attenuation of the virtue."

"Geometry has two great treasures: one is the Theorem of Phythagoras, the other the division of a line in extreme and mean ratio. The first we can compare to a mass of gold; the other we may call a precious jewel."

"I propose to show that God, in creating the universe and arranging the spheres, had in view the five regular solids of geometry, and fixed by their dimensions the number, proportions and motions of the spheres. Take the sphere of the earth as a unit and circumscribe it with a regular dodecahedron. The sphere that contains this dodecahedron is the sphere of Mars."

"Vim coeli reserate viri: venit agnita ad usus: Ignotae videas commoda nulla rei."

"Discover the force of the heavens O Men: Once recognised it can be put to use: No use could be seen in unknown things."

"He who will please the crowd and for the sake of the most ephemeral renown will either proclaim those things which nature does not display or even will publish genuine miracles of nature without regard to deeper causes is a spiritually corrupt person… With the best of intentions I publicly speak to the crowd (which is eager for things new) on the subject of what is to come."

"I believe it was an act of Divine Providence that I arrived just at the time when Longomontanus [Tycho Brahe's assistant before Kepler] was occupied with Mars. For Mars alone enables us to penetrate the secrets of astronomy which otherwise would remain forever hidden from us."

"Every corporeal substance, so far forth as it is corporeal, has a natural fitness for resting in every place where it may be situated by itself beyond the sphere of influence of a body cognate with it."

"Gravity is a mutual affection between cognate bodies towards union or conjunction (similar in kind to the magnetic virtue), so that the earth attracts a stone much rather than the stone seeks the earth."

"...wheresoever the earth may be placed, or whithersoever it may be carried by its animal faculty, heavy bodies will always be carried towards it."

"If the earth were not round, heavy bodies would not tend from every side in a straight line towards the center of the earth, but to different points from different sides."

"If two stones were placed... near each other, and beyond the sphere of influence of a third cognate body, these stones, like two magnetic needles, would come together in the intermediate point, each approaching the other by a space proportional to the comparative mass of the other."

"If the moon and earth were not retained in their orbits by their animal force or some other equivalent, the earth would mount to the moon by a fifty-fourth part of their distance, and the moon fall towards the earth through the other fifty-three parts, and they would there meet, assuming, however, that the substance of both is of the same density."

"If the earth should cease to attract its waters to itself all the waters of the sea would be raised and would flow to the body of the moon."

"The sphere of the attractive virtue which is in the moon extends as far as the earth, and entices up the waters; but as the moon flies rapidly across the zenith, and the waters cannot follow so quickly, a flow of the ocean is occasioned in the torrid zone towards the westward."

"If the attractive virtue of the moon extends as far as the earth, it follows with greater reason that the attractive virtue of the earth extends as far as the moon and much farther; and, in short, nothing which consists of earthly substance anyhow constituted although thrown up to any height, can ever escape the powerful operation of this attractive virtue."

"Nothing which consists of corporeal matter is absolutely light, but that is comparatively lighter which is rarer, either by its own nature, or by accidental heat. And it is not to be thought that light bodies are escaping to the surface of the universe while they are carried upwards, or that they are not attracted by the earth. They are attracted, but in a less degree, and so are driven outwards by the heavy bodies; which being done, they stop, and are kept by the earth in their own place."

"But although the attractive virtue of the earth extends upwards, as has been said, so very far, yet if any stone should be at a distance great enough to become sensible compared with the earth’s diameter, it is true that on the motion of the earth such a stone would not follow altogether; its own force of resistance would be combined with the attractive force of the earth, and thus it would extricate itself in some degree from the motion of the earth."

"I was almost driven to madness in considering and calculating this matter. I could not find out why the planet would rather go on an elliptical orbit. Oh, ridiculous me! As the liberation in the diameter could not also be the way to the ellipse. So this notion brought me up short, that the ellipse exists because of the liberation. With reasoning derived from physical principles, agreeing with experience, there is no figure left for the orbit of the planet but a perfect ellipse."

"It is not improbable, I must point out, that there are inhabitants not only on the moon but on Jupiter too, or (as was delightfully remarked at a recent gathering of certain philosophers) that those areas are now being unveiled for the first time. But as soon as somebody demonstrates the art of flying, settlers from our species of man will not be lacking. Who would once have thought that the crossing of the wide ocean was calmer and safer than of the narrow Adriatic Sea, Baltic Sea, or English Channel? Given ships or sails adapted to the breezes of heaven, there will be those who will not shrink from even that vast expanse. Therefore, for the sake of those who, as it were, will presently be on hand to attempt this voyage, let us establish the astronomy, Galileo, you of Jupiter, and me of the moon."

"No operation of addition or subtraction gives rise to diversity, but all are equally related to their pair of Terms, or Elements."

"Geometry is one and eternal shining in the mind of God. That share in it accorded to humans is one of the reasons that humanity is the image of God."

"Since geometry is co-eternal with the divine mind before the birth of things, God himself served as his own model in creating the world (for what is there in God which is not God?), and he with his own image reached down to humanity."

"Now because 18 months ago the first dawn, 3 months ago broad daylight but a very few days ago the full sun of the most highly remarkable spectacle has risen — nothing holds me back. I can give myself up to the sacred frenzy, I can have the insolence to make a full confession to mortal men that I have stolen the golden vessel of the Egyptians to make from them a tabernacle for my God far from the confines of the land of Egypt. If you forgive me I shall rejoice; if you are angry, I shall bear it; I am indeed casting the die and writing the book, either for my contemporaries or for posterity to read, it matters not which: let the book await its reader for a hundred years; God himself has waited six thousand years for his work to be seen."

"If you want the exact moment in time, it was conceived mentally on 8th March in this year one thousand six hundred and eighteen, but submitted to calculation in an unlucky way, and therefore rejected as false, and finally returning on the 15th of May and adopting a new line of attack, stormed the darkness of my mind. So strong was the support from the combination of my labour of seventeen years on the observations of Brahe and the present study, which conspired together, that at first I believed I was dreaming, and assuming my conclusion among my basic premises. But it is absolutely certain and exact that "the proportion between the periodic times of any two planets is precisely the sesquialterate proportion of their mean distances...""

"The Earth sings Mi-Fa-Mi, so we can gather ever from this that Misery and Famine reign in our habitat."

"The heavenly bodies are nothing but a continuous song for several voices (perceived by the intellect, not by the ear); a music which... sets landmarks in the immeasurable flow of time. It is therefore, no longer surprising that man, in imitation of his creator, has at last discovered the art of figured song, which was unknown to the ancients. Man wanted to reproduce the continuity of cosmic time... to obtain a sample test of the delight of the Divine Creator in His works, and to partake of his joy by making music in the imitation of God."

"The soul of the newly born baby is marked for life by the pattern of the stars at the moment it comes into the world, unconsciously remembers it, and remains sensitive to the return of configurations of a similar kind."

"The wisdom of the Lord is infinite as are also His glory and His power. Ye heavens, sing His praises: sun, moon, and planets, glorify Him in your ineffable language! Praise Him, celestial harmonies, and all ye who can comprehend them! And thou, my soul, praise thy Creator! It is by Him and in Him that all exist."

"Just as the eye was made to see colours, and the ear to hear sounds, so the human mind was made to understand, not whatever you please, but quantity."

"[N]either this nor that supposition is worthy of the name of an astronomical hypothesis, but rather that which is implied in both alike."

"Indeed I reply in a single word to the sentiments of the saints on these questions about nature; in theology, to be sure, the force of authorities is to be weighed, in philosophy, however, that of causes. Therefore, a saint is Lactantius, who denied the rotundity of the earth; a saint is Augustine, who, admitting the rotundity, yet denied the antipodes; worthy of sainthood is the dutiful performance of moderns who, admitting the meagreness of the earth, yet deny its motion. But truth is more saintly for me, who demonstrate by philosophy, without violating my due respect for the doctors of the church, that the earth is both round and inhabited at the antipodes, and of the most despicable size, and finally is moved among the stars."

"[W]ithout proper experiments I conclude nothing..."

"I certainly know that I owe it [the Copernican theory] this duty, that as I have attested it as true in my deepest soul, and as I contemplate its beauty with incredible and ravishing delight, I should also publicly defend it to my readers with all the force at my command."

"Wherever there are qualities there are likewise quantities, but not always vice versa."

"There are, in fact, as I began to say above, not a few principles which are the special property of mathematics, such principles as are discovered by the common light of nature, require no demonstration, and which concern quantities primarily; then they are applied to other things, so far as the latter have something in common with quantities. Now there are more of these principles in mathematics than in the other theoretical sciences because of that very characteristic of the human understanding which seems to be such from the law of creation, that nothing can be known completely except quantities or by quantities. And so it happens that the conclusions of mathematics are most certain and indubitable."

"[Quantity is the fundamental feature of things,] the primarium accidens substantiae,' ...prior to the other categories."

"God gives every animal the means of saving its life—why object if he gives astrology to the astronomer?"

"I was merely thinking God's thoughts after Him. Since we astronomers are priests of the highest God in regard to the book of nature, it benefits us to be thoughtful, not of the glory of our minds, but rather, above all else, of the glory of God."

"The laws of nature are but the mathematical thoughts of God."

"Kepler was the first to discover the art of successfully inquiring [into] her laws of nature, since his predecessors merely constructed explanatory concepts which they endeavoured to apply to the course of nature."

"It is not known so generally that Kepler was... a geometrician and algebraist of considerable power, and that he, Desargues, and perhaps Galileo, may be considered as forming a connecting link between the mathematicians of the renaissance and those of modern times. Kepler's work in geometry consists rather in certain general principles enunciated, and illustrated by a few cases, than in any systematic exposition of the subject. In a short chapter on conics inserted in his Paralipomena, published in 1604, he lays down what has been called the principle of continuity, and gives as an example the statement that a parabola is at once the limiting case of an ellipse and of a hyperbola; he illustrates the same doctrine by reference to the foci of conics (the word focus was introduced by him); and he also explains that parallel lines should be regarded as meeting at infinity. He introduced the use of the eccentric angle in discussing properties of the ellipse."

"Kepler's laws were the climax of thousands of years of an empirical geometry of the heavens. They were discovered as the result of about twenty-two years of incessant calculation, without logarithms, one promising guess after another being ruthlessly discarded as it failed to meet the exacting demands of observational accuracy. Only Kepler's Pythagorean faith in a discoverable mathematical harmony in nature sustained him. The story of his persistence in spite of persecution and domestic tragedies that would have broken an ordinary man is one of the most heroic in science."

"After his own fashion, Desargues discussed... Kepler's principle (1604) of continuity, in which a straight line is closed at infinity and parallels meet there..."

"In his curious tract on Stereometry, published in 1615, Kepler made some advances in the doctrine of infinitesimals. Prompted to the task by a dispute with the seller of some casks of wine, he studied the measurement of solids formed by the revolution of a curve round any line whatever. In solving some of the simplest of these problems, he conceived a circle to be formed of an infinite number of triangles having all their vertices in the centre, and their infinitely small bases in the circumference of the circle, and by thus rendering familiar the idea of quantities infinitely great and infinitely small, he gave an impulse to this branch of mathematics. The failure of Kepler, too, in solving some of the more difficult of the problems which he himself proposed roused the attention of geometers, and seems particularly to have attracted the notice of Cavaleri."

"When Gilbert of Colchester, in his “New Philosophy,” founded on his researches in magnetism, was dealing with tides, he did not suggest that the moon attracted the water, but that “subterranean spirits and humors, rising in sympathy with the moon, cause the sea also to rise and flow to the shores and up rivers”. It appears that an idea, presented in some such way as this, was more readily received than a plain statement. This so-called philosophical method was, in fact, very generally applied, and Kepler, who shared Galileo’s admiration for Gilbert’s work, adopted it in his own attempt to extend the idea of magnetic attraction to the planets."

"Now, if the Earth move, it is a Planet, and shines to them in the Moone, and to the other Planetary inhabitants, as the Moone and they doe vs upon the Earth: but shine she doth, as Galilie, Kepler, and others prove, and then they per consequens, the rest of the Planets are inhabited, as well as the Moone, which he grants in his dissertation with Galilies Nuncius Siderius, that there be Joiviall and Saturnine Inhabitants, &tc. and that those severall Planets, have their severall Moones about them, as the Earth hath hers, as Galileus hath already evinced by his glasses... yet Kepler, the Emperours Mathematitian, confirms out of his experience, that he saw as much, by the same helpe. Then (I say) the Earth and they be Planets alike, inhabited alike, moved about by the Sunne, the common center of the World alike, and it may be those two greene children... that fell from Heaven, came from thence. We may likewise insert with Campanella and Brunus, that which Melissus, Democritus, Leucipus maintained in their ages, there be infinite Worlds, and infinite Earths, or systemes, because infinite starres and planets, like unto this of ours. Kepler betwixtiest and earnest in his Perspectives, Lunar Geography, dissertat cum nunc:syder seemes in part to agree with this, and partly to contradict; for the Planets he yeelds them to be inhabited, he doubts of the Starres: and so doth Tycho in his Astronomicall Epistles, out of consideration of their variety and greatnesse... that he will never beleeve those great and huge Bodies were made to no other use, then this that we perceave, to illuminate the Earth, a point insensible, in respect of the whole. But who shall dwell in these vast Bodies, Earths, Worlds, if they be inhabited? rational creatures, as Kepler demands? Or have they soules to be saved? Or do they inhabit a better part of the World then we doe? Are we or they Lords of the World? ...this only he proves, that we are in the best place, best World, nearest the Heart of the Sun. Thomas Campanella... subscribes to this of Keplerus, that they are inhabited hee certainly supposeth... and that there are infinite worlds, having made an Apologie for Galileus..."

"Kepler's achievements in mathematics would alone have been sufficient to win for him enduring fame; he first enunciated clearly the principle of continuity in mathematics, treating the parabola as at once the limiting case of the ellipse and the hyperbola, and showing that parallel lines can be regarded as meeting at infinity; he introduced the word 'focus' into geometry; while in his Stereometria Dolorum, published 1615, he applied the conception to the solution of certain volumes and areas by the use of infinitesimals, thus preparing the way for Desargues, Cavalieri, Barrow, and the developed calculus of Newton and Leibniz."

"The Neo-Platonic background, which furnished the metaphysical justification for much of this mathematical development (at least as regards its bearing on astronomy) awoke Kepler's full conviction and sympathy. Especially did the aesthetic satisfactions gained by this conception of the universe as a simple, mathematical harmony, appeal vigorously to his artistic nature."

"Founder of exact modern science though he was, Kepler combined with his exact methods and indeed found his motivation for them in certain long discredited superstitions, including what it is not unfair to describe as sunworship."

"The sun, according to Kepler, is God the Father, the sphere of the fixed stars is God the Son, the intervening ethereal medium, through which the power of the sun is communicated to impel the planets around their orbits, is the Holy Ghost."

"Kepler in the first thirty years of the seventeenth century "reduced to order the chaos of data" left by , and added to them just the thing that was needed—mathematical genius. Like Copernicus he created another world-system which, since it did not ultimately prevail, merely remains as a strange monument of colossal intellectual power working on insufficient materials; and even more than Copernicus he was driven by semi-religious fervour—a passion to uncover the magic of mere numbers and to demonstrate the music of the spheres. ...He has to his credit a collection of discoveries and conclusions—some of them more ingenious than useful—from which we today can pick out three that have a permanent importance in the history of astronomy."

"Johannes Kepler... imbibed Copernican principles while at the University of Tubingen. His pursuit of science was repeatedly interrupted by war, religious persecution, pecuniary embarrassments, frequent changes of residence, and family troubles. In 1600 he became for one year assistant to... ... His first attempt to explain the solar system was made in 1596, when he thought he had discovered a curious relation between the five regular solids and the number and distance of the planets. The publication of this pseudo-discovery brought him much fame. At one time he tried to represent the orbit of Mars by the oval curve which we now write in polar coördinates, \rho = 2r cos^3\theta. Maturer reflection and intercourse with Tycho Brahe and Galileo led him to investigations and results worthy of his genius—"Kepler's laws." He enriched pure mathematics as well as astronomy. It is not strange that he was interested in the mathematical science which had done him so much service; for "if the Greeks had not cultivated s, Kepler could not have superseded Ptolemy." The Greeks never dreamed that these curves would ever be of practical use; Aristaeus and Apollonius studied them merely to satisfy their intellectual cravings after the ideal; yet the conic sections assisted Kepler in tracing the march of the planets in their elliptic orbits. Kepler made also extended use of logarithms and decimal fractions, and was enthusiastic in diffusing a knowledge of them. At one time, while purchasing wine, he was struck by the inaccuracy of the ordinary modes of determining the contents of kegs. This led him to the study of the volumes of solids of revolution and to the publication of the Stereometria Doliorum [Vinariorum] in 1615. In it he deals first with the solids known to Archimedes and then takes up others. Kepler made wide application of an old but neglected idea, that of infinitely great and infinitely small quantities. Greek mathematicians usually shunned this notion, but with it modern mathematicians completely revolutionized the science. In comparing rectilinear figures, the method of superposition was employed by the ancients, but in comparing rectilinear and curvilinear figures with each other, this method failed because no addition or subtraction of rectilinear figures could ever produce curvilinear ones. To meet this case, they devised the , which was long and difficult; it was purely synthetical, and in general required that the conclusion should be known at the outset. The new notion of infinity led gradually to the invention of methods immeasurably more powerful. Kepler conceived the circle to be composed of an infinite number of triangles having their common vertices at the centre, and their bases in the circumference; and the sphere to consist of an infinite number of pyramids. He applied conceptions of this kind to the determination of the areas and volumes of figures generated by curves revolving about any line as axis, but succeeded in solving only a few of the simplest out of the 84 problems which he proposed for investigation in his Stereometria. Other points of mathematical interest in Kepler's works are (1) the assertion that the circumference of an ellipse, whose axes are 2a and 2b, is nearly π (a + b); (2) a passage from which it has been inferred that Kepler knew the variation of a function near its maximum value to disappear; (3) the assumption of the principle of continuity (which differentiates modern from ancient geometry), when he shows that a has a focus at infinity, that lines radiating from this "cæcus focus" are parallel and have no other point at infinity. The Stereometria led Cavalieri... to the consideration of infinitely small quantities."

"As I have stated the most remarkable aspect of Kepler's pursuit of science is the constancy with which he applied himself to his chosen quest. To use a phrase of Shelley's his 'was a character superior in singleness'."

"A law explains a set of observations; a theory explains a set of laws. The quintessential illustration of this jump in level is the way in which Newton’s theory of mechanics explained Kepler’s law of planetary motion. Basically, a law applies to observed phenomena in one domain (e.g., planetary bodies and their movements), while a theory is intended to unify phenomena in many domains. Thus, Newton’s theory of mechanics explained not only Kepler’s laws, but also Galileo’s findings about the motion of balls rolling down an inclined plane, as well as the pattern of oceanic tides. Unlike laws, theories often postulate unobservable objects as part of their explanatory mechanism. So, for instance, Freud’s theory of mind relies upon the unobservable ego, superego, and id, and in modern physics we have theories of elementary particles that postulate various types of quarks, all of which have yet to be observed."

"In his 1619 book The Harmony of the World he tells us that he discovered a harmonic law while delivering a lecture on astronomy to his students. Kepler found that for each planet, the cube of the average distance from the sun is proportional to the square of the period of revolution. Kepler later found a similar law for the satellites of Jupiter. Today we know that such a law holds for any system of bodies that circulates around a central parent body. There are many applications of Kepler's law; for instance, half a century later it gave Isaac Newton the clue to his discovery of the law of universal gravitation."

"More than two hundred years before Poncelet, the important concept of a occurred independently to... Johann Kepler... and the French architect Girard Desargues... Kepler (in his Paralipomena in Vitellionem, 1604) declared that a parabola has two foci, one of which is infinitely distant in two opposite directions, and that any point on the curve is joined to this "blind focus" by a line parallel to the axis."

"The effective inventor of the telescope and compound microscope was Galileo... Galileo's account of the path of the rays through the concave eye-piece and convex objective which he used was not satisfactory and was considerably improved by Kepler, who suggested the use of two convex lenses which became the basis of later instruments. Kepler had already written an important optical treatise in the form of a commentary on Witelo's Perspectiva... His improvements to the telescope may be regarded as what he had learned from the thirteenth-century writer."

"With the discovery of the law of inertia and the subsequent downfall of the Aristotelian theory of motion on which Kepler had based his work, his physical theories soon became outmoded and were then rendered obsolete by Newton's work. Yet Kepler's laws of planetary motion remained, so that Edmond Halley could write in his review of Newton's Principia that the first eleven propositions were found to agree with the phenomena of celestial motions, as discovered by the great sagacity and diligence of Kepler."

"Although the concept of heavenly harmony was a theme mentioned in the literature of the time... Kepler's world harmony had little influence on his contemporaries. ...With the rise of the experimental science advocated by Francis Bacon and greatly facilitated by the invention and development of scientific instruments, the general trend of the seventeenth century was towards a mechanical natural philosophy in which metaphysical speculation would play little part. Another factor... may possibly be recognized in the nature of developments that had taken place in mathematics during the sixteenth century, for the advances in algebra and the introduction of symbolism favored a nominalist view of mathematics in contrast to the realist Platonic view of geometry that Kepler adopted as a foundation for his theory of a world harmony."

"When he discovered the polyhedral hypothesis soon after being sent to teach mathematics in Graz, he changed his mind [about becoming a Lutheran minister] , indicating... that he now saw his work in astronomy as an exercise of a priestly vocation. ...he claimed that, in the Harmonice mundi, he offered to the world nothing less than the plan of creation, which God himself had waited six thousand years for someone to comprehend."

"Kepler is the first who ventured here [into] an exact mathematical treatment of the problems (of astronomical science), the first to establish natural laws in the specific sense of the new science."

"Dumbleton was one of the first to express functional relationships in graphical form. ...Dumbleton also gave a proof of the Merton mean-speed rule... stating that "the latitude of a uniformly difform movement corresponds to the degree of the midpoint." He used the method in the Suma [Suma logicæ et philosophiæ naturalis] to study the problem of the variation in the strength of light as a function of the distance from its source. ...He realized that that the decrease in intensity of illumination was not linearly proportional to the distance... But he did not succeed in finding the exact quantitative relationship, which is that the intensity of illumination due to a luminous source is inversely proportional to the square of the distance, a law discovered by Johannes Kepler in 1604."

"I esteem myself happy to have as great an ally as you in my search for truth. I will read your work … all the more willingly because I have for many years been a partisan of the Copernican view because it reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypothesis. To refute the latter I have collected many proofs, but I do not publish them, because I am deterred by the fate of our teacher Copernicus who, although he had won immortal fame with a few, was ridiculed and condemned by countless people (for very great is the number of the stupid)."

"I have as yet read nothing beyond the preface of your book, from which, however, I catch a glimpse of your meaning, and feel great joy on meeting with so powerful an associate in the pursuit of truth, and consequently, such a friend to truth itself; for it is deplorable that there should be so few who care about truth, and who do not persist in their perverse mode of philosophising. But as this is not the fit time for lamenting the melancholy condition of our times, but for congratulating you on your elegant discoveries in confirmation of the truth, I shall only add a promise to peruse your book dispassionately, and with the conviction that I shall find in it much to admire. This I shall do the more willingly because many years ago I became a convert to the opinions of Copernicus, and by his theory have succeeded in explaining many phenomena which on the contrary hypothesis are altogether inexplicable. I have arranged many arguments and confutations of the opposite opinions, which, however, I have not yet dared to publish, fearing the fate of our master, Copernicus, who, although he has earned immortal fame among a few, yet by an infinite number (for so only can the number of fools be measured) is hissed and derided. If there were many such as you I would venture to publish my speculations, but since that is not so I shall take time to consider of it."

"I thank you because you are the first one, and practically the only one, to have complete faith in my assertions."

"To say... that the motion of the Earth meeting with the motion of the Lunar Orb, the concurrence of them occasioneth the Ebbing and Flowing [of the seas], is an absolute vanity, not onely be­cause it is not exprest, nor seen how it should so happen, but the falsity is obvious, for that the Revolution of the Earth is not con­trary to the motion of the Moon, but is towards the same way. So that all that hath been hitherto said, and imagined by others, is, in my judgment, altogether invalid. But amongst all the famous men that have philosophated upon this admirable effect of Nature, I more wonder at Kepler than any of the rest, who being of a free and piercing wit, and having the motion ascri­bed to the Earth, before him, hath for all that given his ear and assent to the Moons predominancy over the Water, and to oc­cult properties, and such like trifles."

"J. Kepler was the first (that I know of) that discover'd the true cause of the Tide, and he explains it largely in his Introduction to the Physics of the Heavens, given in his Commentaries to the Motion of the Planet Mars, where after he has shewn the Gravity or Gravitation of all Bodies towards another, he thus writes: "The Orb of the attracting Power, which is in the Moon is extended as far as the Earth, and draws the Waters under the Torrid Zone, acting upon places where it is vertical, insensibly on included Seas, but sensibly on the Ocean, whose Beds are large, and the Waters have the liberty of reciprocation, that is, of rising and falling"; and in the 70th Page of his Lunar Astronomy,—"But the cause of the Tides of the Sea appear to be the Bodies of the Sun and Moon drawing the Waters of the Sea.""

"Afterwards that incomparable Philosopher Sir Isaac Newton, improv'd the hint, and wrote so amply upon this Subject as to make the Theory of the Tides his own, by shewing that the Waters of the Sea rise under the Moon and the Place opposite to it: For Kepler believ'd "that the Impetus occasion'd by the presence of the Moon, by the absence of the Moon, occasions another Impetus; till the Moon returning, stops and moderates the Force of that Impetus, and carries it round with its motion." Therefore this Spheroidical Figure which stands out above the Sphere (like two Mountains, the one under the Moon and the other in the place opposite to it) together with the Moon (which it follows) is carried by the Diurnal Motion, (or rather, according to the truth of the matter, as the Earth turns towards the East it leaves those Eminencies of Water, which being carried by their own motion slowly towards the East, are as it were unmov'd) in its journey makes the Water swell twice and sink twice in the space of 25 Hours, in which time the Moon being gone from the Meridian of any Place, returns to it again."

"Galileo argued that nature, God's second book, is written in mathematical letters... Kepler is even more explicit in his work on world harmony; he says: God created the world in accordance with his ideas of creation. These ideas are the pure archetypal forms which Plato termed Ideas, and they can be understood by man as mathematical constructs. They can be understood by Man, because Man was created in the spiritual image of God. Physics is reflection on the divine Ideas of Creation, therefore physics is divine service."

"One wonders how many modern scientists faced by a similar situation in their work would fail to be impressed by such remarkable numerical coincidences."

"If Kepler had been a mathematician of the twentieth century, he would have stopped his laborious observational inductions after noting his first law, and deduced the other two analytically."

"Copernicus, Kepler and Galileo were ‘revisionists’ in rejecting the geocentric system of Ptolemy (which held sway for some 1500 years) and, against an oppressive and repressive mainstream opinion (and officialdom), reinstated—with improvements—the heliocentric system of Aristarchos of Samos (3rd cent BCE)."

"Kepler (and Desargues) regarded the two "ends" of the ["straight"] line as meeting at "infinity" so that the line has the structure of a circle. In fact, Kepler actually thought of a line as a circle with its center at infinity."

"Over and above the specific theorems created by men such as Desargues, Pascal and La Hire, several new ideas and outlooks were beginning to appear. The first is the idea of continuous change of a mathematical entity from one state to another... [i.e., of a] a geometrical figure. It was Kepler, in his Astronomiae Optica of 1604, who first seemed to grasp the fact that parabola, ellipse, hyperbola, circle, and the degenerate conic consisting of a pair of lines are continuously derivable from each other. ...The notion of a continuous change in a figure was also employed by Pascal. He allowed two consecutive vertices of his hexagon to approach each other so that the figure became a pentagon. In the same manner he passed from pentagons to quadrilaterals. The second idea to emerge from the work of the projective geometers is that of transformation and invariance."

"The Pythagorean dream of musical harmony governing the motion of the stars never lost its mysterious impact, its power to call forth responses from the depth of the unconscious mind. ...But, one might ask, was the "Harmony of the Spheres" a poetic conceit or a scientific concept. A working hypothesis or a dream dreamt through a mystic's ear? ...Even Aristotle laughed "harmony, heavenly harmony" out of the courts of earnest, exact science. Yet... Johannes Kepler became enamoured with the Pythagorean dream, and on this foundation of fantasy, by methods of reasoning equally unsound, built the solid edifice of modern astronomy. It is one of the most astonishing episodes in the history of thought, and an antidote to the pious belief that the Progress of Science is governed by logic."

"The Harmony of the World is the continuation of the Cosmic Mystery, and the climax of his lifelong obsession. What Kepler attempted here is, simply, to bare the ultimate secret of the universe in an all-embracing synthesis of geometry, music, astrology, astronomy and epistemology. It was the first attempt of this kind since Plato, and it is the last to our day. After Kepler, fragmentation of experience sets in again, science is divorced from religion, religion from art, substance from form, matter from wind."

"Kepler made free use if indivisibles in both astronomical work and a treatise on measuring volumes of wine casks. He went far beyond the practical needs... and wrote an extensive tract on indivisible methods. Two illustrative examples are his approaches to the areas of a circle and an ellipse."

"But to return to Kepler, his great sagacity, and continual meditation on the planetary motions, suggested to him some views of the true principles from which these motions flow. In his preface to the commentaries concerning the planet Mars, he speaks of gravity as of a power that was mutual betwixt bodies, and tells us that the earth and moon tend towards each other, and would meet in a point so many times nearer to the earth than to the moon, as the earth is greater than the moon, if their motions did not hinder it. He adds that the tides arise from the gravity of the waters towards the moon. But not having just enough notions of the laws of motion, he does not seem to have been able to make the best use of these thoughts; nor does he appear to have adhered to them steadily, since in his epitome of astronomy, published eleven years after, he proposes a physical account of the planetary motions, derived from different principles."

"He [Kepler] supposes, in that treatise [epitome of astronomy], that the motion of the sun on his axis is preserved by some inherent vital principle; that a certain virtue, or immaterial image of the sun, is diffused with his rays into the ambient spaces, and, revolving with the body of the sun on his axis, takes hold of the planets and carries them along with it in the same direction; as a load-stone turned round in the neighborhood of a magnetic needle makes it turn round at the same time. The planet, according to him, by its inertia endeavors to continue in its place, and the action of the sun's image and this inertia are in a perpetual struggle. He adds, that this action of the sun, like to his light, decreases as the distance increases; and therefore moves the same planet with greater celerity when nearer the sun, than at a greater distance. To account for the planet's approaching towards the sun as it descends from the aphelium to the perihelium, and receding from the sun while it ascends to the aphelium again, he supposes that the sun attracts one part of each planet, and repels the opposite part; and that the part which is attracted is turned towards the sun in the descent, and that the other part is towards the sun in the ascent. By suppositions of this kind he endeavored to account for all the other varieties of the celestial motions."

"Luckily, Napier came on the scene with his logarithms just when Johannes Kepler, the discoverer of the laws of planetary motion, was deeply immersed in mind-numbing, tedious calculations, filling hundreds of folio pages with lengthy arithmetic operations, in his construction of the orbit of Mars from the observational data of Tycho Brahe. To Kepler, this discovery was a gift from heaven, for logarithms reduced considerably the time he had to spend just doing arithmetic calculations, a task which he detested."

"As living bodies have hair, so does the earth have grass and trees, the cicadas being its dandruff; as living creatures secrete urine in a bladder, so do the mountains make springs; sulphur and volcanic products correspond to excrement, metals and rainwater to blood and sweat; the sea water is the earth's nourishment … At the same time the anima terrae [soul of the earth] is also a formative power (facultas formatrix) in the earth's interior and expresses, for example, the five regular bodies in precious stones and fossils ..... It is important that in Kepler's view the anima terrae is responsible for the weather and also for meteoric phenomena. Too much rain, for instance, is an illness of the earth."

"Kepler also thought of the Inverse Square Law; he thought of it first. ...Kepler regarded gravitational attraction as analogous to propagation of light... Consider now the intensity of light falling on a planet P at a distance R from the Sun. Let S be the total amount if light emitted by the Sun. ...the intensity will be the same at all points distance R from the Sun. But these points constitute a spherical sheet (with center the Sun) whose radius is R and whose surface area, therefore, is 4πR2. Consequently, intensity of radiation =\frac {S}{4\pi}\cdot\frac {1}{R^2}i.e., the intensity is inversely proportional to the square of the distance between the planet P and the Sun. ...Kepler thought carefully about the possibility, but was dubious... to his credit; he mistrusted the idea for a very good reason. ...although during a solar eclipse the Moon blocks the Sun's radiation to part of the Earth, there is no discontinuity in the Earth's motion. If gravitational attraction were radiated as light is radiated, this too would be temporarily blocked by the Moon, so that during the eclipse it would discontinue its eliptical orbit..."

"Kepler was a brilliant thinker and a lucid writer, but he was a disaster as a classroom teacher. He mumbled. He digressed. He was at times utterly incomprehensible. He drew only a handful of students his first year at Graz; the next year there were none. He was distracted by an incessant interior clamour of associations and speculations vying for his attention. And one pleasant summer afternoon, deep in the interstices of one of his interminable lectures, he was visited by a revelation that was to alter radically the future of astronomy. Perhaps he stopped in mid-sentence. His inattentive students, longing for the end of the day, took little notice, I suspect, of the historic moment."

"Kepler's project in was to give 'true and perfect reasons for the numbers, quantities, and periodic motions of celestial orbits.' The perfect reasons must be based on the simple mathematical principles, which had been discovered by Kepler in the solar system, by using geometric demonstrations. The general scheme of his model was borrowed... from Plato's 'Timaeus', but the mathematical relations for the s (pyramid, cube, , , ) were taken by Kepler from the works of Euclid and Ptolemy. Kepler followed Proclus and believed that 'the main goal of Euclid was to build a geometric theory of the so-called Platonic solids.' Kepler was fascinated by Proclus and often quotes him calling him a 'Pythagorean'."

"Nearly three thousand years ago, the ancient Egyptians knew that a glass lens can make an object look bigger. Nero... is said to have looked through an emerald to watch his gladiators fighting... By the ninth century, people were using 'reading stones' to assist their failing eyesight. These were polished lumps of clear glass, rounded on one side and flat on the other; you sat them on top of the document you were trying to read... The first true spectacles were almost certainly invented in Italy between 1280 and 1300. They acted like a magnifying glass and corrected long-sightedness; it would be another 300 years before lenses able to correct short-sightedness would be developed, in part because these were much harder to make. Johannes Kepler (astronomer, astrologer and mathematician) was the first to explain how convex and concave lenses corrected eyesight. ...lenses were (and still are) made by grinding glass using various types of abrasive material, which in Kepler's time were already being used by jewellers."

"Kepler states expressly that he gave the name Foci to certain points related to the conic sections which had previously "no name." With their new name he associated his new views about the points themselves, and his doctrines of Continuity (under the name Analogy) and Parallelism, which would soon have become known, and would after a time have been taken up by competent mathematicians.... A letter of Henry Briggs to Kepler [dated Mar 10, 1625] suggest improvements in the Paralipomena ad Vitellionem. In this letter Briggs... comprehended and accepted Kepler's way of looking at parallels as lines to or from a point at infinity in one direction or its opposite."

"It was only the third new set of planetary tables in European history. And whereas Copernicus's and Ptolemy's tables were more or less equally accurate, Kepler's were some 50 times more so. Within a few years, it was possible to pinpoint the time of transit of Mercury across the face of the sun so that it was possible to observe it in transit for the first time in human history. Of course, Kepler's theories were more difficult, especially since he had incorporated logarithms, which had only been invented a few years earlier. Much of the book, therefore, was made up of explanatory text that told the reader how to use the tables. ...The printing ...was finished on time in September 1627 ...but he was not optimistic ...noting, "There will be few purchasers, as is always the case with mathematical works, especially in the present chaos.""

"We can assume that in a relatively short time — perhaps within 100 million years — the one celled organism evolved into a colony of cells. With the further passage of time, groups of cells within those colonies assumed specialized functions of food-gathering, digestion, the structural features of an outer skin, and so on; thus began the stage of evolution leading to the complex, many-celled creatures which dominate life today. The fossil record contains no trace of these preliminary stages in the development of many-celled organisms. The first clues to the existence of relatively advanced forms of life consist of a few barely discernible tracks, presumably made in the primeval slime by soft, wriggling wormlike animals. These are found in rocks about one billion years old. These meager remains are the earliest traces of many-celled animal life on the planet."

"When a scientist writes about God, his colleagues assume he is either over the hill or going bonkers. In my case it should be understood from the start that I am an agnostic in religious matters. My views on this question are close to those of Darwin, who wrote, "My theology is a simple muddle. I cannot look at the Universe as the result of blind chance, yet I see no evidence of beneficent design in the details.""

"At this moment it seems as though science will never be able to raise the curtain on the mystery of creation. For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries."

"I believe that consciousness is the way information feels when being processed."

"So with each advance in understanding come new questions. So we need to be very humble. We shouldn't have hubris and think that we can understand everything. But history tells us that there is good reason to believe that we will continue making fantastic progress in the years ahead."

"If I get a parking ticket, there is always a parallel universe where I didn't. On the other hand, there is yet another universe where my car was stolen."

"... I would rather have questions that I can't answer than answers that I can't question. (variation of a remark by Richard Feynman)"

"Yet the complexity of all this pales in comparison to the patterns of information processing in your brain. Your roughly 100 billion neurons are constantly generating electrical signals (“firing”), which involves shuffling around billions of trillions of atoms, notably sodium, potassium, and calcium ions. The trajectories of these atoms form an extremely elaborate braid through spacetime, whose complex intertwining corresponds to storing and processing information in a way that somehow gives rise to our familiar sensation of self-awareness. There’s broad consensus in the scientific community that we still don’t understand how this works, so it’s fair to say that we humans don’t yet fully understand what we are. However, in broad brush, we might say this: You’re a pattern in spacetime. A mathematical pattern. Specifically, you’re a braid in spacetime—indeed, one of the most elaborate braids known."

"Imagine all the food you have eaten in your life and consider that you are simply some of that food, rearranged."

"We have to get away from this idea today with some fact-checking sites which might themselves have an agenda and you just trust it because of its reputation. You want to have these sort of systems [where] they earn your trust and that is completely transparent."

"Evolution endowed us with intuition only for those aspects of physics that had survival value for our distant ancestors, such as the parabolic orbits of flying rocks (explaining our penchant for baseball). A cavewoman thinking too hard about what matter is ultimately made of might fail to notice the tiger sneaking up behind and get cleaned right out of the gene pool. Darwin’s theory thus makes the testable prediction that whenever we use technology to glimpse reality beyond the human scale, our evolved intuition should break down. We’ve repeatedly tested this prediction, and the results overwhelmingly support Darwin. At high speeds, Einstein realized that time slows down, and curmudgeons on the Swedish Nobel committee found this so weird that they refused to give him the Nobel Prize for his relativity theory. At low temperatures, can flow upward. At high temperatures, colliding particles change identity; to me, an electron colliding with a and turning into a Z-boson feels about as intuitive as two colliding cars turning into a cruise ship. On microscopic scales, particles schizophrenically appear in two places at once, leading to the quantum conundrums... On astronomically large scales... weirdness strikes again: if you intuitively understand all aspects of black holes... put down this book and publish your findings before someone scoops you on the Nobel Prize for quantum gravity… [also,] the leading theory for what happened [in the early universe] suggests that space isn’t merely really really big, but actually infinite, containing infinitely many exact copies of you, and even more near-copies living out every possible variant of your life in two different types of parallel universes."

"What is real? Is there more to reality than meets the eye? Yes! was Plato’s answer over two millennia ago. In his famous cave analogy, he likened us to people who’d lived their entire lives shackled in a cave, facing a blank wall, watching the shadows cast by things passing behind them, and eventually coming to mistakenly believe that these shadows were the full reality. Plato argued that what we humans call our everyday reality is similarly just a limited and distorted representation of the true reality, and that we must free ourselves from our mental shackles to begin comprehending it."

"I... ended up at the , focusing on environmental issues. I wanted to... make our planet a better place, and felt that the main problem... [was] that we didn't properly use... technology... I... was intrigued by... creating economic incentives that aligned... egoism with the common good. ...I soon grew disillusioned, concluding that economics was... intellectual prostitution... rewarded for saying what the powers that be wanted to hear. ...[T]he book that changed everything: ' ...[W]hat did Feynman see that I missed in high school? ...I sat down with... '... and started reading, "If... all scientific knowledge were to be destroyed... " ...I read on ...I felt like I was having a religious experience I finally got it!"

"[W]hat I had been missing... and what Feynman realized: physics is the ultimate intellectual adventure, the quest to understand the deepest mysteries of our Universe. ...[I]t makes us see more clearly, adding to the beauty and wonder of the world ...[T]he lens of physics adds more beauty to the world ..."

"So this book... [is] my personal quest for the ultimate nature of reality."

"We're all born with curiosity, but at some point, school usually manages to knock that out of us. ...[M]y main responsibility as a teacher isn't to convey facts, but to rekindle that lost enthusiasm for asking questions."

"[W]e've repeatedly underestimated not only the size of our cosmos, but also the power of our human mind to understand it."

"There's no better guarantee of failure than convincing yourself that success is impossible..."

"Eratosthenes... knew that the Sun was straight overhead in... Syene at noon on the summer solstice, but that it was 7.2 degrees south of straight overhead in , located 794 kilometers farther north. He concluded... 794 kilometers corresponded to 7.2 degrees out of the 360 degrees... around Earth's circumference, so that the circumference must be... 39,700 km..."

"Aristarchos of Samos... was able to use to figure out... the distance between the Earth and the Sun. His conclusion... the Sun was about twenty times farther... than the Moon and therefore twenty times bigger than the Moon. In other words, the Sun was... over five times bigger than the Earth in diameter. This insight prompted Aristarchos to propose the heliocentric hypothesis long before Nicolaus Copernicus... It turned out to be quite difficult to tell precisely when the Moon was 50% illuminated, and the correct Sun-Moon angle... isn't 87 degrees but about 89.85 degrees... This makes... the Sun... almost twenty times further away... and about 109 times larger than the Earth... [T]his wasn't corrected until almost two thousand years later, so when Copernicus came along... the overall scale of his Solar System model was about twenty times too small..."

"Some ancients speculated that the stars were small holes in a black sphere through which distant light shone through. ...Giordano Bruno suggested that they were... like our Sun, just much farther away, perhaps with their own planets and civilizations... the Catholic Church had him burned at the stake in 1600."

"The very fabric of our physical world, space itself, could be a purely mathematical object in the sense that its only intrinsic properties are mathematical... as dimensionality, and topology."

"... achieved a breakthrough. Please hold your thumb at arm's length and alternate closing your left and right eyes a few times. ...[Y]our thumb appears to jump left and right by a certain angle relative to the background... [M]ove your thumb closer... and you'll see this jump angle growing. Astronomers call this jump angle '... [W]e can... compare telescopic photographs taken six months apart, when Earth is on opposite sides of the Sun. ...Bessel noticed ... ...moved a tiny angle, revealing its distance to be almost a million times that to the Sun... Now that Bessel knew the distance he used... [the] to figure out how luminous it was... in the same ballpark as the Sun... Giordano Bruno had been right after all!"

"In 1814... Joseph von Fraunhofer invented... a spectrograph, which let him separate white light into into a rainbow of colors... He discovered mysterious dark lines in the rainbow... and... the detailed positions of these lines... depended on what the light source was made of, constituting a kind of spectral fingerprint. During the following decades such spectra were measured and catalogued for many... substances. ...Sensationally, the spectrum of sunlight revealed that the Sun... contained elements... such as . Moreover... it revealed that stars are made of roughly the same mixture of gases as the Sun! This clinched it in favor of Bruno: stars are distant suns..."

"(…) the '. Here we interpret the wavefunction for an object as describing not some funky imaginary ensemble of possibilities for what the object might be doing, but rather the actual spatial collection of identical copies of the object that exist in our infinite space. Moreover, quantum uncertainty that you experience simply reflects your inability to self-locate in the Level I multiverse, i.e., to know which of your infinitely many copies throughout space is the one having your subjective perceptions."

"It’s absolutely crucial that we don’t conflate this internal reality with the external reality that it’s tracking, because the two are very different. My brain’s internal reality is like the dashboard of my car: a convenient summary of the most useful information. Just as my car’s dashboard tells me my speed, fuel level, motor temperature, and other things useful for a driver to be aware of, my brain’s dashboard/reality model tells me my speed and position, my hunger level, the air temperature, highlights of my surroundings and other things useful for the operator of a human body to be aware of."

"(…) the bottom line is that if you believe in an external reality independent of humans, then you must also believe that our physical reality is a mathematical structure. Nothing else has a baggage-free description. In other words, we all live in a gigantic mathematical object—one that’s more elaborate than a dodecahedron, and probably also more complex than objects with intimidating names such as Calabi-Yau manifolds, tensor bundles and Hilbert spaces, which appear in today’s most advanced physics theories. Everything in our world is purely mathematical—including you."

"A famous thorny issue in philosophy is the so-called infinite regress problem. For example, if we say that the properties of a diamond can be explained by the properties and arrangements of its carbon atoms, that the properties of a carbon atom can be explained by the properties and arrangements of its protons, neutrons and electrons, that the properties of a proton can be explained by the properties and arrangements of its quarks, and so on, then it seems that we’re doomed to go on forever trying to explain the properties of the constituent parts. The Mathematical Universe Hypothesis offers a radical solution to this problem: at the bottom level, reality is a mathematical structure, so its parts have no intrinsic properties at all!"

"(…) time is not an illusion, but the flow of time is. So is change. In spacetime, the future exists and the past doesn’t disappear."

"This implication of the Mathematical Universe Hypothesis is pretty radical, so please pause (…) take it in and think about it. What you’re aware of right at this moment feels not like a photo but like a movie clip. This movie isn’t reality—it exists only in your head, as part of your brain’s reality model. It contains lots of information about the actual external physical reality—as long as you aren’t dreaming or hallucinating—but still constitutes only a very heavily edited version of reality, akin to the evening news on TV, mainly featuring certain highlights of patterns nearby in space and time that your brain thinks are useful for you to be aware of."

"(…) no spectator is needed, because your consciousness basically is your reality model. I think that consciousness is the way information feels when being processed in certain complex ways. Since the different parts of your brain interact with each other, different parts of your reality model can interact with each other, so the model of you can interact with your model of the outside world, giving rise to the subjective sensation of the former perceiving the latter."

"My guess is that we’ll one day understand consciousness as yet another phase of matter. I’d expect there to be many types of consciousness just as there are many types of liquids, but in both cases, they share certain characteristic traits that we can aim to understand."

"We humans replace the bulk of both our "hardware" (e.g., our cells) and our "software" (e.g., our memories) many times in our life span. Nonetheless, we perceive ourselves as stable and permanent. Likewise, we perceive objects other than ourselves as permanent. Or rather, what we perceive as objects are those aspects of the world that display a certain permanence. For instance, when observing the ocean, we perceive the moving waves as objects because they display a certain permanence, even though the water itself is only bobbing up and down. Similarly (…) we perceive only those aspects of the world that are fairly stable against quantum decoherence."

"If there’s a singularity, would the resulting AI, or AIs, feel conscious and self-aware? Would they have an internal reality? If not, they’re for all practical purposes zombies. Of all traits that our human form of life has, I feel that consciousness is by far the most remarkable. As far as I’m concerned, it’s how our Universe gets meaning, so if our Universe gets taken over by life that lacks this trait, then it’s meaningless and just a huge waste of space."

"But I’ve suddenly changed my mind and turned more optimistic about our cosmic significance. Why? Because I’ve come to believe that advanced evolved life is very rare, yet has huge future potential, making our place in space and time remarkably significant."

"Let’s instead define life very broadly, simply as a process that can retain its complexity and replicate. What’s replicated isn’t matter (made of atoms) but information (made of bits) specifying how the atoms are arranged. When a bacterium makes a copy of its DNA, no new atoms are created, but a new set of atoms are arranged in the same pattern as the original, thereby copying the information. In other words, we can think of life as a self-replicating information-processing system whose information (software) determines both its behavior and the blueprints for its hardware."

"How is technology changing the hierarchical nature of our world? History reveals an overall trend toward ever more coordination over ever-larger distances, which is easy to understand: new transportation technology makes coordination more valuable (by enabling mutual benefit from moving materials and life forms over larger distances) and new communication technology makes coordination easier. When cells learned to signal to neighbors, small multicellular organisms became possible, adding a new hierarchical level. When evolution invented circulatory systems and nervous systems for transportation and communication, large animals became possible. Further improving communication by inventing language allowed humans to coordinate well enough to form further hierarchical levels such as villages, and additional breakthroughs in communication, transportation and other technology enabled the empires of antiquity. Globalization is merely the latest example of this multi-billion-year trend of hierarchical growth."

"Why is at the beginning of time so low, and the entropy in a black hole so high? ...We ...don't know that the entropy was low ...We don't even know if there was a beginning of time. ...[E]ntropy ...is this measure of how messy things are, so my room ...tends to get higher and higher entropy, messier and messier. Why... eggs fall on the floor and break, and not fly up and unbreak? People argued about that for a very long time until the shocking insight... that it was very low 13.4 billion years ago at the time when those baby pictures of the universe were given off... the cosmic microwave background. So our flow of time... has something to do with the origin of our universe? That... we have learned. ...[I]f you take seriously the idea of inflation and also the theory that the does not collapse, according to Hugh Everett, you can do some math and get an explanation... but... it's a wonderful mystery, and I'm open to all ideas... and black holes... there are great truths yet to be discovered."

"For Neils Bohr and the Copenhagen interpretation, I respond with Hamlet, "Something is rotten in the state of Denmark." ...The does not collapse. ...There is absolutely no experimental evidence for it. It appears to collapse, yes, but what Hugh Everett showed so beautifully... in the... 50s and 60s is that even if it does not collapse... If you just drop that entirely and just... go with the Schrödinger equation all the way, it's going to appear like it collapses... according to all the usual Copenhagen interpretation rules... [I]t doesn't even have anything particularly fundamental to do with quantum mechanics. ...If you have any sort of physics which lets you make copies of an observer, classically or quantum mechanically, you will experience apparent randomness. ...Suppose you ...clone yourself ...so you can get twice as much done? ...One copy ...wakes up in Room 1 and the other... in Room 2... Are you going to see... a sign that says Room 1 or will you see a 2? You cannot predict this... because... there will be two experiences. ...It seems random. I'm going to see either... with equal probability. This is what fundamentally is happening in quantum physics too. The quantum reality is just bigger than the one we thought we lived in before quantum mechanics, and it has this ability that it can start with something which is one way and make [it] effectively being in two ways. [W]hen we make a measurement, sometimes we find out which copy we were. So I wouldn't worry too much about the way a function collapse[s]."

"It depends... on what you measure outrageousness in... If what you mean is that something is more extravagant if it... involves somehow having more particles, or reality being bigger... then sure. But... maybe the kind of simplicity that we should value with Occam's razor is rather that the math is simple. The equations are simple."

"Here... is the Schrödinger equation [i \hbar \frac{d}{d t}\vert\Psi(t)\rangle = \hat H\vert\Psi(t)\rangle]... and what it's actually saying is that the state of the world, that's this Greek letter Ψ there with the bracket around it... It's saying that the rate of change of it... depends on the current state of the world, when you do this operation on it and for the math nerds, this is a linear operation... and what that just means is, as Everett has pointed out and many others have known for a very long time is that, in some circumstances, two different solutions to this can do their parallel thing. We can talk at... length about the discoveries... about decoherence and why it is that sometimes these different parallel branches are unaware or each other, but my point is... if you give a science nerd colloquium... at a physics department... ideally, you should also start in the same way you start discussing this with your grandma. Just at a very high level... here are the cool ideas, and then you can go as deep as the audience or the listener wants, from there."

"We don't know for sure that the Schrödinger equation is actually that accurate a description of nature either. That's why it's so exciting to see what's going to happen with the quantum computer efforts... Will they ultimately fail because physics isn't fully described by the Schrödinger equation, or will they actually succeed... This is where ultimately our experimental friends will... give us crucial insights..."

"I'll be the first to admit that we ultimately don't know what's going on exactly with quantum mechanics, and my personal guess... is that even quantum mechanics is probably an emergent theory, maybe an approximation of... something deeper. Maybe we can get it out of GU somehow, but... I also would guess... the opposite of Roger Penrose... that gravity doesn't really have much to do with this. I think you can... be in a spaceship far away... from any... important gravitating objects and do your little quantum experiments with a Schrödinger-like apparatus and you would get all the same fascinating things happening. So... ignoring gravity... ignoring relativistic effects altogether, you still have this thing people love fighting about. Does the wave function collapse or not, and that's why I'm so interested in this kind of discussion..."

"[I]t's... a big mistake as a species if we don't create institutions and governments which support science. There have been a number of... economic studies that have shown... that investing in basic science is the highest return on investment, basically ever... Inventing the ... just basic... physics research... has benefited us so much, in so many ways... Inventing calculus... didn't cost that much, but it's... so, so valuable... This comes back to the whole media question again. There are much more people who have heard about the Kardashians than... can name three living scientists... let alone twenty. ...[W]e've created a culture where scientists... not only are they not particularly known... or viewed as role models or heroes, but they are even very actively attacked by... folks with power with whom what scientists are saying is inconvenient... One of the best things we can do for science funding is to create a less screwed-up media landscape where we actually appreciate how much we benefit from scientific research. That governments will actually support it again. ...We spend two billion dollars a day or more, in this county alone, on military... If you can get a puny, puny fraction of that into scientific research, we wouldn't even be having to have this conversation about how we get funding."

"My favorite movie of all time is... Life of Brian. We really should try and reenact this epic skit, "What have the Romans ever done for us?" by saying "What has physics ever done for us? ...But ...besides ...the internet and transistors, what has physics ever done for us?""

"Physicists, we have a sort of arrogance... which has harmed us a lot. ...We forget that we're in a bubble and ...that there's actually a science of how you persuade people ...of how to communicate, and other people have studied that at great length. ...[T]he average person who works making cigarette ads is much more scientific about the way they get their message out than the average physicist. ...[I]t comes not from stupidity ...but from arrogance ...We're not going to stoop so low that we're going to be scientific about how we communicate... about how we advocate. We have to get off our high horses... If you get invaded by Hitler's army, you shouldn't just say... "Tanks are immoral, we're going to fight them with swords." We have to be scientific also about standing up for ourselves and our ideas... A second mistake... spending much more time infighting within our community of physicists, or... having one science pitted against another... for a few more tax dollars... losing sight of the fact that there's a tiny trickle of money that flows to all of the sciences combined... compared to... generic fruits of... corporate lobbying and random waste... So, get out of our bubble again. If we look at the big picture, it's kind of pathetic... that you have physicists, biologists, chemists, who together have built up most of the wealth of the world, and managed to be so incredibly navel-gazing and busy with infighting, and old-fashioned in how they communicate, that they have to come begging for money, and people don't listen to them."

"Tegmark’s career is a rather unusual story, mixing reputable science with an increasingly strong taste for grandiose nonsense. In this book he indulges his inner crank, describing in detail an utterly empty vision of the "ultimate nature of reality." What's perhaps most remarkable about the book is the respectful reception it seems to be getting... Before publishing his first paper, he changed his name from Shapiro to Tegmark (his mother’s name), figuring that there were too many Shapiros in physics for him to get attention... A very odd aspect of this whole story is that while Tegmark's big claim is that Math=Physics, he seems to have little actual interest in mathematics and what it really is as an intellectual subject. ...[W]hile "mathematical structures" are invoked in the book as the basis of everything, there's little to no discussion of the mathematical structures that modern mathematicians find interesting (although the idea of "symmetries" gets a mention). ...Perhaps the explanation of all this is somehow Freudian, since Tegmark’s father is the mathematician Harold Shapiro."

"The primary challenge of this cosmological transformation of consciousness is the awareness that each being in the universe is an origin of the universe. "The center of the cosmos" refers to that place where the great birth of the universe happened at the beginning of time, but it also refers to the upwelling of the universe as river, as star, as raven, as you, the universe surging into existence anew. The consciousness that learns it is at the origin point of the universe is itself an origin of the universe. The awareness that bubbles up each moment that we identify as ourselves is rooted in the originating activity of the universe. We are all of us arising together at the center of the cosmos."

"Earth was once molten rock, and now it makes spaceships."

"This is the greatest discovery of the scientific enterprise: You take hydrogen gas, and you leave it alone, and it turns into rosebushes, giraffes, and humans."

"With the appearance of the human, the coding process of life burst beyond the DNA molecule and began carving its information in stone!"

"If you if you take Buddhism and Christianity and so forth there's a kind of battle — a subtle sort of struggle taking place because they're not standing in a common ground but … take the Earth or ecology then suddenly they can begin to explore what they have to offer. So I do think I do think absolutely that … there will be a flourishing of religions, not a withering away. And they will flourish to the degree that they will move into the context of planet and universe. I even think that as a matter of fact that … some of the central insights of the religions are more powerfully presented by what we know about the universe now then when they were first formulated."

"There's a great phrase from Eric Jantsch … and he says, "these self-organizing dynamics are in every place in the universe, waiting at their marks". I love that phrase because you get that … the power for making water exists everywhere in the universe but the conditions have to be right. But if the conditions are right, then these self-organizing dynamics leap to it. So I think it's something like that, that the possibility for sentience has always been there but has been waiting for a chance to really display."

"The more I learn about light the more I realize, man, we don't know anything about light... It's just bizarre... a particle has its own proper time which slows down as you speed up. But at the speed of light... there's no time. That's bizarre … that we can, right now, as you know, see — interact with the light that has come from the birth of the universe. So … from our point of view, that light traveled for 14 billion years but from the point of view of the light it's the moment of creation."

"I think the discovery of nonlocality is touching in on the whole. So that these these seemingly separate events are somehow connected through the whole. … you have this larger enveloping field and we're, you know, just beginning to understand something about that... so I love that discovery although I don't think we're anywhere near really knowing what we've come upon."

"The break-through moments are unimaginable until they happen."

"I have a sense that something amazing is at work … I think our planet is actually moving into a time of profound harmony and fecundity and peace but whether that's going to take 600 years or 6 days I don't know. I mean, I think that as humans begin to take seriously... the planetary dimension of conscious self-awareness, then we will become homonized versions of natural selection — so that we will begin to make decision with the large scale dynamic of the planet in mind. So I see that we're actually entering into a transformation of the human species out of the modern period into this new era... It may take centuries... but like the past and it's catastrophes I think that's... what's taking place in the midst of so many hardships."

"What's evil for the hawk is the mouse because, you know, the mouse is quick and gets away but I did this one realization every scientist goes through at one point... if you gave the hawk power, the power of God, the first thing the hawk might do is to slow down the mouse. But then the hawk would lose it's speed. And then if you slow the mouse all the way down, so it can just barely move, the hawk would lose its flight. So that in a weird way the tension between those two say natural enemies is what gives birth to their beauty. So I definitely feel that the tension we have right now within the human community in particular — that those are ultimately going to be resolved with a deeper harmony and a deeper appreciation for one another."

"Every moment we're making decisions. If you want to understand the universe as a whole you'd have to include all those decisions including our own lives so that even in the future our presence is going to be felt one way or the other — so I think … our death as being — it's a death to a micro-phase self or a small self … it's a death into our larger self in that … this whole vast adventure is our larger identity."

"There are two other words I do not understand — awareness and intelligence. Well, why am I talking about things when I do not know what they really mean? It is probably because I am a mathematician and mathematicians do not mind so much about that sort of thing. They do not need precise definitions of the things they are talking about, provided they can say something about the connections between them."

"Some years ago, I wrote a book called The Emperor's New Mind and that book was describing a point of view I had about consciousness and why it was not something that comes about from complicated calculations. So we are not exactly computers. There's something else going on and the question of what this something else was would depend on some detailed physics and so I needed chapters in that book, which describes the physics as it is understood today. Well anyway, this book was written and various people commented to me and they said perhaps I could use this book for a course Physics for Poets or whatever it is if it didn't have all that contentious stuff about the mind in that. So I thought, well, that doesn't sound too hard, all I'll do is get out the scissor out and snip out all the bits, which have something to do with the mind. The trouble is that if I did that — and I actually didn't do it — the whole book fell to pieces really because the whole driving force behind the book was this quest to find out what could it be that constitutes consciousness in the physical world as we know it or as we hope to know it in future"

"Understanding is, after all, what science is all about — and science is a great deal more than mindless computation."

"Does life in some way make use of the potentiality for vast quantum superpositions, as would be required for serious quantum computation? How important are the quantum aspects of DNA molecules? Are cellular microtubules performing some essential quantum roles? Are the subtleties of quantum field theory important to biology? Shall we gain needed insights from the study of quantum toy models? Do we really need to move forward to radical new theories of physical reality, as I myself believe, before the more subtle issues of biology — most importantly conscious mentality — can be understood in physical terms? How relevant, indeed, is our present lack of understanding of physics at the quantum/classical boundary? Or is consciousness really “no big deal,” as has sometimes been expressed? It would be too optimistic to expect to find definitive answers to all these questions, at our present state of knowledge, but there is much scope for healthy debate..."

"Moreover, the complete details of the complication of the structure of Mandelbrot's set cannot really be fully comprehended by anyone of us, nor can it be fully revealed by any computer. It would seem that this structure is not just part of our minds, but it has a reality of its own. ... The computer is being used in essentially the same way that the experimental physicist uses a piece of experimental apparatus to explore the structure of the physical world. The Mandelbrot set is not an invention of the human mind: it was a discovery. Like Mount Everest, the Mandelbrot set is just there!"

"I have been arguing that such 'God-given' mathematical ideas should have some kind of timeless existence, independent of our earthly selves."

"Gödel's theorem shows that this point of view is not really a tenable one in a fundamental philosophy of mathematics. The notion of mathematical truth goes beyond the whole concept of formalism. There is something absolute and 'God-given' about mathematical truth. This is what , as discussed at the end of the last chapter, is about. Any particular formal system has a provisional and 'man-made' quality about it. Such systems indeed have very valuable roles to play in mathematical discussions, but they can supply only a partial (or approximate) guide to truth. Real mathematical truth goes beyond mere man-made constructions."

"It seems to me that we must make a distinction between what is "objective" and what is "measurable" in discussing the question of physical reality, according to quantum mechanics. The state-vector of a system is, indeed, not measurable, in the sense that one cannot ascertain, by experiments performed on the system, precisely (up to proportionality) what the state is; but the state-vector does seem to be (again up to proportionality) a completely objective property of the system, being completely characterized by the results it must give to experiments that one might perform."

"What right do we have to claim, as some might, that human beings are the only inhabitants of our planet blessed with an actual ability to be "aware"? … The impression of a "conscious presence" is indeed very strong with me when I look at a dog or a cat or, especially, when an ape or monkey at the zoo looks at me. I do not ask that they are "self-aware" in any strong sense (though I would guess that an element of self-awareness can be present). All I ask is that they sometimes simply feel!"

"How is it that mathematical ideas can be communicated in this way? I imagine that whenever the mind perceives a mathematical idea, it makes contact with Plato's world of mathematical concepts. ... When one 'sees' a mathematical truth, one's consciousness breaks through into this world of ideas, and makes direct contact with it ('accessible via the intellect'). I have described this 'seeing' in relation to Gödel's theorem, but it is the essence of mathematical understanding. When mathematicians communicate, this is made possible by each one having a direct route to truth, the consciousness of each being in a position to perceive mathematical truths directly, through this process of 'seeing'. (Indeed, often this act of perception is accompanied by words like 'Oh, I see'!) Since each can make contact with Plato's world directly, they can more readily communicate with each other than one might have expected. The mental images that each one has, when making this Platonic contact, might be rather different in each case, but communication is possible because each is directly in contact with the same externally existing Platonic world!"

"According to this view, the mind is always capable of this direct contact. But only a little may come through at a time. Mathematical discovery consists of broadening the area of contact. Because of the fact that mathematical truths are necessary truths, no actual 'information', in the technical sense, passes to the discoverer. All the information was there all the time. It was just a matter of putting things together and 'seeing' the answer! This is very much in accordance with Plato's own idea that (say mathematical) discovery is just a form of remembering! Indeed, I have often been struck by the similarity between just not being able to remember someone's name, and just not being able to find the right mathematical concept. In each case, the sought-for concept is in a sense already present in the mind, though this is a less usual form of words in the case of an undiscovered mathematical idea."

"It is hard for me to believe, as some have tried to maintain, that such SUPERB theories could have arisen merely by some random natural selection of ideas leaving only the good ones as survivors. The good ones are simply much too good to be the survivors of ideas that have arisen in that random way. There must, indeed, be some deep underlying reason for the accord between mathematics and physics, i.e. between Plato's world and the physical world."

"It is hard to see how one could begin to develop a quantum-theoretical description of brain action when one might well have to regard the brain as "observing itself" all the time!"

"Beneath all this technicality is the feeling that it is indeed "obvious" that the conscious mind cannot work like a computer, even though much of what is involved in mental activity might do so. This is the kind of obviousness that a child can see—though the child may, later in life, become browbeaten into believing that the obvious problems are "non-problems", to be argued into nonexistence by careful reasoning and clever choices of definition. Children sometimes see things clearly that are obscured in later life. We often forget the wonder that we felt as children when the cares of the "real world" have begun to settle on our shoulders. Children are not afraid to pose basic questions that may embarrass us, as adults, to ask. What happens to each of our streams of consciousness after we die; where was it before we were born; might we become, or have been, someone else; why do we perceive at all; why are we here; why is there a universe here at all in which we can actually be? These are puzzles that tend to come with the awakenings of awareness in any one of us—and, no doubt, with the awakening of self-awareness, within whichever creature or other entity it first came."

"Do not seek for reasons in the specific patterns of stars, or of other scattered arrangements of objects; look, instead, for a deeper universal order in the way that things behave."

"...the entire physical world is depicted as being governed according to mathematical laws. We shall be seeing in later chapters that there is powerful (but incomplete) evidence in support of this contention. On this view, everything in the physical universe is indeed governed in completely precise detail by mathematical principles — perhaps by equations, such as those we shall be learning about in chapters to follow, or perhaps by some future mathematical notions fundamentally different from those which we would today label by the term ‘equations’. If this is right, then even our own physical actions would be entirely subject to such ultimate mathematical control, where ‘control’ might still allow for some random behaviour governed by strict probabilistic principles."

"It is quite likely that the 21st century will reveal even more wonderful insights than those that we have been blessed with in the 20th. But for this to happen, we shall need powerful new ideas, which will take us in directions significantly different from those currently being pursued. Perhaps what we mainly need is some subtle change in perspective—something that we all have missed...."

"[C]razy ideas are the sort of thing one needs when talking about the Big Bang. ...All the ideas I'm going to show you... are put forward by very... respectable cosmologists. It doesn't make the ideas any less crazy..."

"I'm not sure what Friedmann actually said, but he... produced a model in which the universe... started in a Big Bang... expanded to a maximum size... then would shrink down to a crunch, and then start all over again. ...There would be several Big Bangs and before each one, would be a collapsing phase of the universe..."

"[T]here's a version of this a version of this idea which John Wheeler has promoted, which is that in each of these cycles, since nobody really knows what goes on at the crunch, bang stage... you can... invent any physics you like, and one idea... is to suggest that the... fundamental constants of nature might get changed every time you go through one of these cycles... [T]his might help to explain... puzzles that... the constants have to be just such and such in order that life should exist...[etc.] I always have trouble with many of these arguments. It's not at all clear whether you need them or not. They might be true but we don't know. It may be that these numbers are fixed and they might change through each cycle...[etc.] but our current physics... doesn't allow this kind of thing. These are singular states according to classical theory. Maybe if we had quantum gravity... one could imagine such a scheme..."

"Somewhat more exotic is the idea... by Lee Smolin in his book... [T]hese pictures are a little hard to draw... The difficulty seems... a... drawback. It may mean... something... troublesome about the geometry. ...[W]e have black holes forming ...You must imagine each one of these forming ...take this funnel ...that's supposed to represent the universe ...which expands from the Big Bang and ...its expansion accelerates because of ... or, if you're more boring like me, the cosmological constant ...and according to Smolin, all these black holes, which form at various places, could be the origins of new universes, and you see them sprouting off at various places... [Y]ou can adopt the Wheeler idea of maybe having the constants of nature changing to reach one of these phases."

"If you want fantasy... first of all, you have to believe in string theory... these extra dimensions and the D brains... and these D brains are supposed to have collided in the period before the Big Bang and there they come together and produced our Big Bang... and that expands... [T]he trouble... is a strong element of fantasy. We really haven't the remotest idea... what kind of physics is supposed to go on here, but there's a more serious problem... [T]his... has different forms, one... is... in terms of the 2nd law of thermodynamics... and it's related to a geometrical issue... [T]hese pictures are hard to draw.... because the singularity in the black hole doesn't really fit on the Big Bang singularity... It's a stretch of geometrical imagination... [I]t doesn't make them wrong, because... you really do need some fantasy, and this is an example of this possible kind of fantasy that you might need, but I want to give you a different kind which... has some greater plausibility..."

"In its simplest form, the 2nd law of thermodynamics... You imagine... a glass of wine sitting on a table... it falls off and wine splashes out onto the carpet...[etc.] If you just think of this as a Newtonian situation, as the system evolves the thing proceeds according to Newtonian laws, but Newtonian laws are reversible in time... What's not so agreeable [about the reverse] is that it violates the 2nd law..."

"The 2nd law of thermodynamics... tells you that randomness increases with time. It's a sort of depressing law... It depends on how you look at it, really..."

"[T]he randomness is measured... by... entropy, and it's telling us that this entropy is increasing with time. ...[I]t can be given a clearer definition ...the idea due to Boltzmann ...we imagine... a ... a space... of a very large number of dimensions, where each point in the space represents a state of the system at one moment. In fact it contains both the positions of all the particles and the momenta (or velocities) of all the particles. So if you know where the point is in this large dimensional space at any moment that describes a particular thing... then the dynamics will tell you where that point moves. So that there will be a unique path through that point, wiggling around somewhere through this phase space."

"[S]ome of these regions may be... indistinguishable, for example the air in the room. We might have molecules in some other places. You might like to say we don't care where the individual molecules are. We just care about overall parameters, and so we lump together the systems which look very much the same. ...[L]et's say with regard to macroscopic parameters we lump them together, and so we have these things called course graining cells in the phase space... [Y]ou then say, well let's measure the volume of these regions... V... and the logarithm of that volume is the entropy. This is a marvelous formula due to Boltzmann. This [k] is Boltzmann's constant, the only thing in the formula that wasn't due to Boltzmann... This was named afterwards. I don't think he was particularly interested in constants..."

"It's a very plausible thing now that the entropy should increase all the time... [T]hese volumes... are... enormously different in scale... I can't convey to you in the picture the absolute stupendous difference in the sizes of these volumes. So if you happen to find yourself in one of them, and you wiggle around, the next one you find yourself in will be overwhelmingly likely to be much much larger, and the entropy therefor goes up."

"General relativity is certainly a very beautiful theory, but how does one judge the elegance of physical theories generally?"

"The idea of having an ambient space-time of some specific dimension seems to play less of a role of string theory than in conventional physics, and certainly less than the kind of role that I would myself feel comfortable with. It is particularly difficult to assess the functional freedom that is involved in a physical theory unless one has a clear idea of its actual space-time dimensionality."

"One is left with the uneasy feeling that even if supersymmetry is actually false, as a feature of nature, and that accordingly no supersymmetry partners are ever found by the LHC or by any later more powerful accelerator, then the conclusion that some supersymmetry proponents might come to would not be that supersymmetry is false for the actual particles of nature, but merely that the level of supersymmetry breaking must be greater even that the level reached at that moment, and that a new even more powerful machine would be required to observe it!"

"What the anthropic principle depends upon is the idea that whatever is the nature of the universe, or universe portion that we see about us, being subject to whatever dynamical laws govern its actions, this must be strongly favourable to our very existence."

"Whereas originally the hopes for string theory, and its descendants, were that some kind of uniqueness would be arrived at, whereby the theory would supply mathematical explanations for the measured numbers of experimental physics, the string theorists were driven to find refuge in the strong anthropic argument in an attempt to narrow down an absolutely vast number of alternatives. In my own view, this a very sad and unhelpful place for a theory to find itself."

"Reading about the lives of geniuses can be a powerful antidote against any envy we might feel for not being among their number. Almost invariably they turn out not only to have had the same flaws, trials and heartbreaks as the rest of us but to be deeply weird to boot. The Nobel Prize-winning British physicist Roger Penrose certainly fits the template."

"Although I'm regarded as a dangerous radical by particle physicists for proposing that there may be loss of quantum coherence, I'm definitely a conservative compared to Roger. I take the positivist viewpoint that a is just a and that it is meaningless to ask whether it corresponds to reality. All that one can ask is that its predictions should be in agreement with observation. I think Roger is a Platonist at heart but he must answer for himself."

"[I]n the June, 1960 issue of... the ', there appeared a paper by... Roger Penrose with the esoteric title "A Approach to General Relativity." Although the paper was highly mathematical, it outlined a very elegant and streamlined technique for solving certain problems in general relativity. ...this new method made some computations almost easy."

"(By moving) I'm making sounds on the drums of spacetime"… "Space itself wobbles and rumbles like a drum... Black holes can bang on spacetime like mallets on a drum."

"People used to try to hijack quantum mechanics and its inherent mystery to cast a cloud around determinism, in the hope that free will could survive modern physics. But that never worked very well. Since when does random chance equal free will? The only salvation for volition is a soul and faith and you’re not allowed to ask me about that."

"It might seem limited to impose our human perception to try to deduce the grandest cosmic code. But we are the product of the universe and I think it can be argued that the entire cosmic code is imprinted in us. Just as our genes carry the memory of our biological ancestors, our logic carries the memory of our cosmological ancestry. We are not just imposing human-centric notions on a cosmos independent of us. We are progeny of the cosmos and our ability to understand it is an inheritance."

"Topology and number theory are my faves."

"Theoretical physicists live in a classical world, looking out into a quantum-mechanical world. The latter we describe only subjectively, in terms of procedures and results in our classical domain."

"The concept of 'measurement' becomes so fuzzy on reflection that it is quite surprising to have it appearing in physical theory at the most fundamental level... does not any analysis of measurement require concepts more fundamental than measurement? And should not the fundamental theory be about these more fundamental concepts?"

"A final moral concerns terminology. Why did such serious people take so seriously axioms which now seem so arbitrary? I suspect that they were misled by the pernicious misuse of the word ‘measurement’ in contemporary theory. This word very strongly suggests the ascertaining of some preexisting property of some thing, any instrument involved playing a purely passive role. Quantum experiments are just not like that, as we learned especially from Bohr. The results have to be regarded as the joint product of ‘system’ and ‘apparatus,’ the complete experimental set-up."

"I am a Quantum Engineer, but on Sundays I Have Principles."

"While the founding fathers agonized over the question 'particle' or 'wave', de Broglie in 1925 proposed the obvious answer 'particle' and 'wave'. Is it not clear from the smallness of the scintillation on the screen that we have to do with a particle? And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave? De Broglie showed in detail how the motion of a particle, passing through just one of two holes in screen, could be influenced by waves propagating through both holes. And so influenced that the particle does not go where the waves cancel out, but is attracted to where they cooperate. This idea seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored."

"It can be argued that in trying to see behind the formal predictions of quantum theory we are just making trouble for ourselves. Was not precisely this the lesson that had to be learned before quantum mechanics could be constructed, that it is futile to try to see behind the observed phenomena?"

"The theorem tells you that maybe there must be something happening faster than light, although it pains me even to say that much. The theorem certainly implies that Einstein's concept of space and time, neatly divided up into separate regions by light velocity, is not tenable. But then, to say that there's something going faster than light is to say more than I know."

"The discomfort that I feel is associated with the fact that the observed perfect s seem to demand something like the ‘genetic’ hypothesis [identical twins, carrying with them identical genes]. For me, it is so reasonable to assume that the photons in those experiments carry with them programs, which have been correlated in advance, telling them how to behave. This is so rational that I think that when Einstein saw that, and the others refused to see it, he was the rational man. The other people, although history has justified them, were burying their heads in the sand. I feel that Einstein’s intellectual superiority over Bohr, in this instance, was enormous; a vast gulf between the man who saw clearly what was needed, and the obscurantist. So for me, it is a pity that Einstein’s idea doesn’t work. The reasonable thing just doesn’t work."

"Bohr was inconsistent, unclear, willfully obscure and right. Einstein was consistent, clear, down-to-earth and wrong."

"To know the quantum mechanical state of a system implies, in general, only statistical restrictions on the results of measurements. It seems interesting to ask if this statistical element be thought of as arising, as in classical statistical mechanics, because the states in question are averages over better defined states for which individually the results would be quite determined. These hypothetical 'dispersion free' states would be specified not only by the quantum mechanical state vector but also by additional 'hidden variables' - 'hidden' because if states with prescribed values of these variables could actually be prepared, quantum mechanics would be observably inadequate."

"More generally, the hidden variable account of a given system becomes entirely different when we remember that it has undoubtedly interacted with numerous other systems in the past and that the total wave function will certainly not be factorable. The same effect complicates the hidden variable account of the theory of measurement, when it is desired to include part of the 'apparatus' in the system. Bohm of course was well aware of these features of his scheme, and has given them much attention. However, it must be stressed that, to the present writer's knowledge, there is no proof that any hidden variable account of quantum mechanics must have this extraordinary character. It would therefore be interesting, perhaps, to pursue some further 'impossibility proofs,' replacing the arbitrary axioms objected to above by some condition of locality, or of separability of distant systems."

"1 + P(b, c) ≥ |P(a, b) － P(a, c)|"

"In a theory in which parameters are added to quantum mechanics to determine the results of individual measurements, without changing the statistical predictions, there must be a mechanism whereby the setting of one measuring device can influence the reading of another instrument, however remote. Moreover, the signal involved must propagate instantaneously, so that such a theory could not be Lorentz invariant. Of course, the situation is different if the quantum mechanical predictions are of limited validity. Conceivably they might apply only to experiments in which the settings of the instruments are made sufficiently in advance to allow them to reach some mutual rapport by exchange of signals with velocity less than or equal to that of light. In that connection, experiments of the type proposed by Bohm and Aharonov, in which the settings are changed during the flight of the particles, are crucial."

"Surely, after 62 years, we should have an exact formulation of some serious part of quantum mechanics? By 'exact' I do not of course mean 'exactly true'. I mean only that the theory should be fully formulated in mathematical terms, with nothing left to the discretion of the theoretical physicist . . . until workable approximations are needed in applications. By 'serious' I mean that some substantial fragment of physics should be covered. Nonrelativistic 'particle' quantum mechanics, perhaps with the inclusion of the electromagnetic field and a cut-off interaction, is serious enough."

"I agree with them about that: ORDINARY QUANTUM MECHANICS (as far as I know) IS JUST FINE FOR ALL PRACTICAL PURPOSES. Even when I begin by insisting on this myself, and in capital letters, it is likely to be insisted on repeatedly in the course of the discussion. So it is convenient to have an abbreviation for the last phrase: FOR ALL PRACTICAL PURPOSES = FAPP."

"I expect that mathematicians have classified such s. Certainly they have been much used by physicists. But is there not something to be said for the approach of Euclid? Even now that we know that is (in some sense) not quite true? Is it not good to know what follows from what, even if it is not necessarily FAPP? Suppose for example that quantum mechanics were found to resist precise formulation. Suppose that when formulation beyond FAPP was attempted, we find an unmovable finger obstinately pointing outside the subject, to the mind of the observer, to the Hindu scriptures, to God, or even only Gravitation? Would that not be very, very interesting?"

"The concepts 'system', 'apparatus', 'environment', immediately imply an artificial division of the world, and an intention to neglect, or take only schematic account of, the interaction across the split. The notions of 'microscopic' and 'macroscopic' defy precise definition. So also do the notions of 'reversible' and 'irreversible'."

"Einstein said that it is theory which decides what is . I think he was right—'observation' is a complicated and theory-laden business. Then that notion should not appear in the formulation of fundamental theory. Information? Whose information? Information about what? On this list of bad words from good books, the worst of all is 'measurement'. It must have a section to itself."

"The first charge against 'measurement', in the fundamental axioms of quantum mechanics, is that it anchors there the shifty split of the world into 'system' and 'apparatus'. A second charge is that the word comes loaded with meaning from everyday life, meaning which is entirely inappropriate in the quantum context."

"The idea that elimination of coherence, in one way or another, implies the replacement of 'and' by 'or', is a very common one among solvers of the 'measurement problem'. It has always puzzled me."

"The orthodox approaches, whether the authors think they have made derivations or assumptions, are just fine FAPP — when used with the good taste and discretion picked up from exposure to good examples."

"We must thank John Bell for having shown us that philosophical questions about the nature of reality could be translated into problems for physicists, where naive experimentalists can contribute."

"I had never met Bell, nor heard him lecture, but in my reading of his scientific papers I have developed a great admiration for him and his work. I have especially admired his attempts to dismantle the orthodox Copenhagen interpretation of quantum theory, written with such tremendous style and obvious enjoyment. Although in this book I have tried to present a balanced account - arguing one way and then another - I hope that I have done justice to Bell's superbly constructed criticisms. The debate over the meaning of quantum theory will certainly be poorer without him."

"I told Wheeler that I had had a number of conversations with Bell about quantum theory. "He’s a wonderful fellow," Wheeler noted. "Did he say to you," Wheeler asked, laughing, "‘I’d rather be clear and wrong, than foggy and right’?" I told Wheeler that Bell had not used exactly those words, but that it certainly sounded like him. I also told Wheeler that from the time that Bell began to study the quantum theory, he had conceptual problems with it, and that I had asked Bell if, at that time, he thought that the theory might simply be wrong—to which Bell had answered, "I hesitated to think it might be wrong, but I knew that it was rotten." At this, Wheeler burst into a marvelous peal of laughter. The idea of the young Bell rebelling against the "rottenness" of the quantum theory struck Wheeler as incredibly funny."

"In my opinion, John Bell performed an extremely important role then, and also later, in generally supporting - thereby making respectable - the apparently "fringe" activities of such people as Karolyhazy, Bohm, [Philip M.] Pearle, Ghirardi, and many others (including myself) in suggesting schemes that go beyond standard quantum mechanics, in the intended direction of realism. No physicist could doubt the scientific credentials of John Bell. The fact that he was prepared to go out of his way to support research of this kind gave it a previously unaccustomed status."

"It was John Bell who investigated quantum theory in the greatest depth and established what the theory can tell us about the fundamental nature of the physical world. Moreover, by stimulating experimental tests of the deepest and most profound aspects of quantum theory, Bell's work led to the possibility of exploring seemingly philosophical questions, such as the nature of reality, directly through experiments. And this was just Bell's "hobby"."

"John S. Bell (1928–1990, right) and I at in Bell’s office 10 years after the neutrino experiment. We were the quasi-official theorists of that experiment. We did not do very well, all things considered, because of inexperience and ignorance. After the experiment, in 1963, we both went to SLAC, where I wrote my computer program and he developed his famous inequalities. We also discussed other things, even wrote a paper together that was never published. He considered his work on the fundaments of quantum mechanics as a hobby, mainly to be done in the evening, at home. He told me that he intended to do away definitely with this nonsense of hidden variables, and so he did. Later he drifted more and more into this subject, and as I consider it as some sort of foolishness not good for anything having to do with the real world, I once asked him: “Why are you doing this? Does it make the slightest difference in the calculations such as I am doing?” To which he answered: “You are right, but are you not interested and curious about the interpretation?” He was right too, up to a point. While his work became very important, as it could be verified by experiment, often in this branch of physics the discussions are on the level of finding out how many angels can dance on the point of a needle. But even so: there are interesting things there."

"Let us admit that no matter how small the chance it could happen, one molecule could be created by such astronomical odds of chance. However, one molecule is of no use. Hundreds of millions of identical ones are necessary. Thus we either admit the miracle or doubt the absolute truth of science."

"One example of these kinds of statistics comes from Evolution: Possible or Impossible by James F. Coppedge [who] cites an article by Ulric Jelinek … which claims that the odds are 1 in 10^243 against "two thousand atoms" (the size of one particular protein molecule) ending up in precisely that particular order "by accident." Where did Jelenik get that figure? From Pierre Lecompte du Nouy... who in turn got it from Charles-Eugene Guye, a physicist who died in 1942. Guye had merely calculated the odds of these atoms lining up by accident if "a volume" of atoms the size of the Earth were "shaken at the speed of light," failing to factor in laws of chemistry, which create preferences for the formation and behavior of molecules, and ignoring that there are millions if not billions of different possible proteins. This calculation comes to Coppedge third-hand, and is now outdated (it was calculated before 1942, even before the discovery of DNA)."

"A theorist can explain any correlation, and its inverse."

"It is not surprising that it was the Greeks, with their profound understanding of geometrical principles, who were the first to devise methods of measuring the size of the earth and the distance to the sun and the moon. Indeed, their results were not superseded until the eighteenth century, when telescopes had been developed to the point where new methods could be introduced."

"... I started thinking about gravitational theories and Mach's Principle and so on, I knew already then, very slightly, Hermann Bondi and Tommy Gold, and I talked to them a bit about these things, I remember I asked Bondi to tea one day and told him the thoughts I'd had and I said, "Are they rubbish? What should I do?" He said, "Why not go on thinking about them?" I think that was very good of him, because I'm quite sure in retrospect it was rubbish what I said, as I was very immature at that time ..."

"You know my favourite Dirac story: I go up to him once and I say, "Professor Dirac, I've just thought of a way of relating the formation of stars to cosmological things — not galaxies, stars — shall I tell you about it?" And he said, "No.""

"It has now become clear that the exploration of the Universe, as conducted by physicists, astronomers and cosmologists, is one of the greatest intellectual adventures of the mid-twentieth century."

"The reader has by now probably become accustomed to the reversals of fortune so common in astronomy."

"Главное, делайте всё с увлечением, это страшно украшает жизнь."

"This work contains many things which are new and interesting. Unfortunately, everything that is new is not interesting, and everything which is interesting, is not new."

"In the 1930s Landau was already saying, "I am one of the few universal physicists"; after the death of Enrico Fermi, this became "I am the last of the universal physicists"."

"A method is more important than a discovery, since the right method will lead to new and even more important discoveries."

"People who hear of some extraordinary phenomenon start proposing to explain it with improbable hypotheses. First consider the simplest explanation: that it's all nonsense."

"The idea seems to exist that there can be an absolutely continuous transition between the liquid and crystalline state (analogous to the transition liquid-gas), which would require the existence of a miraculous state which is neither isotropic nor anisotropic."

"BEWARE, HE BITES!"

"In 1958, Landau and certain other seminar participants were highly enthusiastic about the new Heisenberg theory in which all particles arise from a universal fermion field. (Others, however, took a highly skeptical view of this theory.) At one seminar Landau received a letter through Pontecorvo, supposedly from Pauli, and Landau read it aloud. In the brief letter, Pauli wrote that he liked Heisenberg's theory, that he'd found new arguments in its favor and found it highly plausible. Moreover, wrote Pauli, the latest experiments with Λ hyperons confirm Heisenberg's theory. No details were given about these experiments, though. There was great excitement: after all, Pauli was known as a person with a critical turn of mind, far from gullible. Different hypotheses were advanced; one young theorist even went up to the board and tried to imagine what the experiment could be that Pauli wrote of. Meanwhile, Migdal took the letter, read it carefully and said, "Something's strange here. If you read the first letters of all the lines from top to bottom, it spells the Russian word 'fools.' What could that mean?" The secret was simple: The letter was written by Migdal and Pontecorvo."

"It is Landau’s invention—as it may, I feel, be fairly called—of the order parameter that is so important but often underappreciated... Landau’s concept of the order parameter, indeed, brought light, clarity, and form to the general theory of phase transitions, leading eventually, to the characterization of multicritical points and the understanding of many characteristic features of ordered states. But in 1944 a bombshell struck! Lars Onsager, by a mathematical tour de force, deeply admired by Landau himself, computed exactly the partition function and thermodynamic properties of the simplest model of a ferromagnet or a fluid... the nature of the critical singularities disagreed profoundly—as I will explain below—with essentially all the detailed predictions of the Landau theory (and of all foregoing, more specific theories)."

"In 1956 Shapiro had been very actively investigating the so-called $\tau-\theta$ problem, which had been puzzling physicists for a long time. Shapiro came to the conclusion that the only possible explanation could be the parity non-conservation in this decay of mesons... Landau, when Shapiro presented him the paper, laughed at such an idea -- without Landau's holy consent Shapiro's paper could not be published. It remained on his desk, where I saw it many months before Lee and Yang submitted their paper for publication. So, because of Landau, Soviet physics lost one Nobel prize. A similar case is reported by Landau's closest collaborator, A.A. Abrikosov. Landau's negative attitude to Abrikosov's theory had delayed the discovery of superconductivity II for about four years."

"Once, lecturing in Moscow during his last visit to the USSR, Niels Bohr was asked how he had succeeded in creating such a famous and first-class school of theoretical physics. He answered: "Probably because I have never been ashamed of admitting to my students that I am a fool." Bohr's lecture was translated into Russian by Landau's closest collaborator, E. Lifshitz, who translated it: "Probably because I have never been ashamed to tell my students that they are fools." Lifshitz's mistranslation caused a lot of laughter among the listeners. Lifshitz became aware of his mistake, corrected himself, and apologized. Kapitza, who was present, remarked that this mistranslation had not been accidental at all: "Precisely here lies the difference between Bohr's and Landau's schools of theoretical physics.""

"Don't trust your teachers."

"Listening to a cultivated person of today who jokes and almost boasts of his scientific ignorance is as sad as listening to a scientist who boasts of not having read any poem."

"Hawking was one of the good physicists of his generation, not the universal genius the popular press has depicted. It is a pity, because this confusion fogs the memory of a remarkable man."

"If we want to understand the past we must do so on its own terms, and disregard the future of that past, but if we want to understand the present we better not disregard the past steps that were essential for getting to the present. This is of importance especially for those of us engaged in trying to push ahead the scientific path of discovery today. We are not much interested in what scientists did wrong, there is too much of that. We are interested in what they did right, because we are trying to copy them in this, not in that."

"... theoretical physics is less clean than the way it's usually solved. You can always change parameters and save yourself. ... it's very rare that theories are ruled out by just an experiment or a group of experiments. Theories usually come with flexibility. Theoreticians can add flexibility. And so new experiments — you can just patch up your theory."

"The landscape is magic, the trip is far from being over."

"I think that physics is about escaping the prison of the received thoughts and searching for novel ways of thinking the world, about trying to clear a bit the misty lake of insubstantial dreams, which reflect reality like the lake reflects the mountains."

"The new coherent picture is not yet available. With all their immense empirical success, G(eneral)R(elativity) and Q(uantum)M(echanics) have left us with an understanding of the physical world which is unclear and badly fragmented. At the foundations of physics there is today confusion and incoherence."

"An overly pragmatic attitude is not productive in the long run."

"I argue that the best strategy for understanding quantum gravity is to build a picture of the physical world where the notion of time plays no role at all."

"[I]n a fundamental description of nature we must "forget time"... this can be done in the classical and in the quantum theory."

"I... interpret mechanics as a theory of relations between variables, rather than the theory of the evolution of variables in time."

"General relativity has changed our understanding of space and time. ...The spacetime of general relativity ...is likely to be just a classical approximation that loses its meaning in the quantum theory, for the same reason the trajectory of a particle does."

"The notion of time familiar to us may... be reconstructed in special physical situations, or within an approximation, as... the "surface of a liquid" disappears ...[at] the atomic level, or "temperature" ...makes sense only in certain physical situations and when there are enough degrees of freedom."

"I am aware that ...[this] answer ...is only one among many possibilities. Other authors have argued that the notion of time is irreducible... Until our theoretical and experimental investigations tell us otherwise... what is important is to put the alternatives clearly on the table..."

"[I]n pre-relativistic mechanics, time is a special physical quantity, whose value is measured by physical clocks, that plays the role of the independent variable of physical evolution."

"While non-relativistic time is the observable quantity measured (or approximated) by physical clocks, in general relativity clocks measure s along their worldline, not t. The relativistic... t is a freely chosen label with no direct physical interpretation. ...The physical content of a solution of Einstein's equations is not in its dependence on t, but ...in what remains once the dependence on t (and x) has been factored away."

"What is then the physical content of a solution of Einstein's equations..? ...[C]onsider what is actually measured in general relativistic experiments. ...Consider a clock at rest on ...Earth and a clock on a satellite in orbit around the Earth. ...Call T1 and T2 the readings... Each measures the along its own worldline, in the Earth gravitational field. ...the theory predicts the value of T2 that will be associated to each value of T1. Or vice versa."

"[I]n general relativistic observations there is no preferred independent time variable. What we measure are a number of variables, all on equal footing, and their relative evolution. ...[I]t can be equally read it as the evolution of the variable T1 as a function of the variable T2, or viceversa. Which of the two is the independent variable here?"

"The way evolution is treated in general relativity, is... subtle... Change is not described as evolution of physical variables as a function of a preferred independent observable time variable. Instead, it is described in terms of a functional relation among equal footing variables... as... (T1,T2)... In general relativity, there isn’t a preferred and observable quantity that plays the role of independent parameter of the evolution... General relativity describes the relative evolution of observable quantities, not the evolution of quantities as functions of a preferred one. ...[w]ith general relativity we have understood that the Newtonian "big clock" ticking away the "true universal time" is not there."

"If we formulate the fundamental theory of nature in a timeless language, we have then the problem of recovering the familiar notion of time."

"Intuitively (and imprecisely) speaking, time "flows", we can never "go back in time", we remember the past but not the future, and so on. Where do all these very peculiar features of the time variable come from? ...[T]hese features... emerge at the thermodynamical level. ...[T]hese are all features that emerge when we give an approximate statistical description of a system with a large number of ."

"Whatever the statistical state ρ is, there exists always a variable tρ, measured by the thermal clock, with respect to which the system is in equilibrium and physics is the same as in the conventional nonrelativistic statistical case! This observation leads us to the following hypothesis."

"The thermal time hypothesis. In nature, there is no preferred physical time variable t. There are no equilibrium states ρ0 preferred a priori. Rather, all variables are equivalent; we can find the system in an arbitrary state ρ; if the system is in a state ρ, then a preferred variable is singled out by the state of the system. This variable is what we call time."

"[I]t is the statistical state that determines which variable is physical time, and not any a priori hypothetical "flow" that drives the system to a preferred statistical state. When we say that a certain variable is “the time”, we are not making a statement concerning the fundamental mechanical structure of reality. Rather, we are making a statement about the statistical distribution we use to describe the... properties of the system... The "thermal time hypothesis" is the idea that what we call "time" is the thermal time of the statistical state in which the world happens to be, when described in terms of the macroscopic parameters we have chosen."

"Time is... the expression of our ignorance of the full microstate."

"In his youth Albert Einstein spent a year loafing aim- lessly. You don’t get anywhere by not ‘wasting’ time – something, unfortunately, which the parents of teenagers tend frequently to forget."

"A handful of types of elementary particles, which vibrate and fluctuate constantly between existence and non-existence and swarm in space even when it seems that there is nothing there, combine together to infinity like the letters of a cosmic alphabet to tell the immense history of galaxies, of the innumerable stars, of sunlight, of mountains, woods and fields of grain, of the smiling faces of the young at parties, and of the night sky studded with stars."

"Children grow up and discover that the world is not as it seemed within the four walls of their homes. Humankind as a whole does the same."

"The idea that a well-defined now exists throughout the universe is an illusion, an illegitimate extrapolation of our own experience"

"When two friends meet... after one has lived in the mountains and the other at sea level, the watches... will show different times. ...Neither is truer than the other. ...Times are legion: a different one for every point in space. ...there is a vast multitude of them. ...Every clock has its proper time. ...Einstein has shown how to calculate the difference... The world is not like a platoon advancing at the pace of a single commander. It is a network of events affecting each other. ...Physics does not describe how things evolve "in time" but how things evolve in their own times, and how "times" evolve relative to each other. Time has lost... its unity."

"The difference between past and future... cause and effect... memory and hope... regret and intention... in the elementary laws that describe the mechanisms of the world, there is no such difference."

"In the elementary equations of the world, the arrow of time appears only where there is heat. The link between time and heat is... fundamental: every time a difference is manifested between the past and the future, heat is involved."

"The World is Made of Events, not Things."

"But it isn’t absence that causes sorrow. It is affection and love. Without affection, without love, such absences would cause us no pain. For this reason, even the pain caused by absence is, in the end, something good and even beautiful, because it feeds on that which gives meaning to life."

"If I move one watch, put it higher, and wait a little bit... with very good clocks, and today we can... you bring it [back] down, and this [the clock that was higher] is ahead, this [the clock that remained lower] is behind. ...The clock up, has measured more time than the clock down. And it's not just a matter of clocks. Everything, ...if you are high ...a flower would blossom more, a machine would do more cycles ...more things happening up than down. Of course, the difference is small, otherwise we would have noticed it ...earlier."

"Quite remarkably, this was understood before having good clocks... It is one of great intuitions by Einstein. In 1915 he completed the theory of relativity... At the time clocks were not good enough... it was a theory, a good speculation... Today it is not a theory... It's a fact that we measure in the labaratory. ...It's so clear and definite that technology needs this to be taken into account."

"GPS... gets messages from satellites. On those satellites are clocks... The satellites broadcast the times and your little device use the time to tringulate wherever you are... [W]hen this was built the physicists told the [engineers] that were putting up the system, "Careful, up there... your clocks are going to run faster..." ...The entire project was controlled by the American army ...supervised by the generals ...[who] didn't believe it. So the first satellites were put up there with a switch... and of course it does not work if you do not take this into account. ...You would crash the car against the wall, driving with the navigator if we didn't [take] this into account ..."

"This means that the time between [points on a line] is 24 hours here but... more if you're... higher, and less if you're less [high]. ...Now it's measurable to 30-40 cm [difference in] altitude in the lab."

"What makes the difference is the mass. ...[T]he earth is a big mass and it slows down time. If you go to a bigger mass, like Jupiter, it's stronger. If you go near a big star it's stronger. If you're near a black hole... it's even more strong, so strong that if you go very near... time essentially stops down. It goes very, very, very slowly."

"If we had a starship, we could move near a black hole, stay there for a half hour and then come out. Outside hundreds of years could have gone. So we could... come away from the black hole into the far future easily."

"[T]ime is much more elastic than our intuition of this rigid passage... The time interval between one point and another... depends on where you are."

"[I]n "Helgoland" Rovelli explains his "relational" interpretation, in which an electron, say, has properties only when it interacts... When it is not interacting, the electron is devoid of physical properties: no position... velocity... trajectory. ...[T]he electron's properties are real only for the object it's interacting with and not for other objects. ...Rovelli's lyricism may depend on how many other ...accounts of quantum physics one may have read: The more that number, the more "Helgoland" will seem a poem."

"'... is a magnificent example of the adage "less is more". Tackling everything from quantum physics and cosmology to particle physics, space-time and black holes in so few words... Rovelli... managed... with aplomb. ...The Order of Time ...is a little more conventional ...the first part covering ..., the arrow of time, relativity, synchronization and the notion of Planck time... The second part imagines a world without time, while [in] the third Rovelli wonders how we perceive a flow of time in a timeless world. ...[H]e has a deep technical knowledge ...he knows what the hell he’s talking about ...Rovelli can condense complex ideas into beautifully written prose, gently guiding the reader through mind-bending ideas without... cliché or stale metaphors. Anecdotes, history, art, philosophy and culture pepper the text."

"[W]hile we scientists know how to use [quantum physics]... [w]e don't know what it's telling us about the fundamental nature of reality. It is into that chasm that... Rovelli leaps with his new book Helgoland. ...Rovelli is one of the world's leading theoretical physicists. He is also a lyrical writer whose previous bestsellers have offered beautiful meditations on "the adventure of science." ...What quantum mechanics is teaching us, Rovelli says, is that reality is a vast net of interactions where there are no things, only relationships. ...Helgoland is not... a book to learn quantum mechanics from. ...Rovelli is offering a new way to understand not just the world but our place in it ..."

"With the fate of Schrödinger's cat in the balance and Heisenberg's idea that quantum theory only describes observations, Rovelli inevitably asks the tricky questions: what is observation? What is an observer? ...He is the champion of the "relational" interpretation... [that] quantum theory does not describe the way in which quantum objects manifest themselves to "observers", but... how every physical object manifests itself to every other physical object. The world we observe is... better understood as a web of interactions and relations rather than objects."

"Rovelli talks about time as a complex collection of layers and then strips away those layers... I find an elegant grandeur in how he relates the worlds of science, philosophy and art. What’s more, scientists and philosophers, going back to ancient times, have weaved a connection between poetry and physics, or, as it was once called, "." ...I can think of no one other than Rovelli who would begin all but one chapter of his nonfiction book with excerpts from the "Odes" of Horace. That single aberrant chapter... quotes Shakespeare’s "Henry IV, Part I." ...Rovelli’s new story of time is elegant and lucidly told, whether he is revealing facts or indulging in romantic-philosophic speculation about the nature of time."

"The beauty of physics lies in its precise statements, and that is what is essential to convey. Many readers won’t have the background required to distinguish fact from speculation. Words can turn equations into poetry, but elegant language shouldn’t come at the expense of understanding. Rovelli isn’t the first author guilty of such romanticizing... But when deceptively fluid science writing permits misleading interpretations to seep in, I fear that the floodgates open to more dangerous misinformation."

"Wedging old ideas into new thinking is analogous to equating thousand-dollar couture adorned with beads and feathers and then marketed as "tribal fashion" to homespun clothing with true cultural and historical relevance. Ideas about relativity or gravity in ancient times weren’t the same as Einstein’s theory. Art (and science) are in the details. Either elementary matter is extended or it is not. The universe existed forever, or it had a beginning. Atoms of old aren’t the atoms of today. Egg and flour are not a soufflé. Without the appropriate care, it all just collapses."

"Carlo Rovelli... is one of the great scientific explicators of our time. His... '... remains the world's fastest selling science book. ...The Order of Time and ' ...illuminated ...Einsteinian relativity, gravitational waves and other ...physics. ...Rovelli's gift is to bring difficult ideas down a level. His books continue a tradition of jargon-free popular scientific writing from Galileo to Darwin that disappeared in the academic specializations of the last century."

"Is the earth affected by its cosmological setting in the universe? It is to be presumed that the solar system was molded at its birth by galactic conditions which in turn reflected the primordial chaos of the primitive galaxy. However, we are not concerned here with questions of this type, interesting though they are, but rather with a problem of even grander proportions: Is there an effect upon the earth, here and now, of the distribution of matter in the universe? As the universe expands, as distant matter moves away from us, are there effects upon the earth of this changing distribution of matter?"

"A for which the entrance area, covered with a very large number of randomly distributed pinholes, is 50 per cent open is shown to be a very effective way of forming images of a complex of s. A simple statistical trick is used to reduce the multitudinous overlapping images to a single image. Less than forty detected photons are needed to form an image of a single star."

"In Heisenberg's , the transferred to the particle by the scattered photon makse the particle's momentum uncertain. It is shown that momentum is also transferred when the lack of a scattered photon is used to discover that the particle is absent from the field of view of the microscope (i.e., located outside the light beam). This apparent paradox, a transfer of momentum and/or energy to a missing particle by a light beam (without the scattering of a photon), is discused and "resolved" using quantum measurement theory."

"I have long believed that an experimentalist should not be unduly inhibited by theoretical untidyness. If he insists in having every last theoretical T crossed before he starts his research the chances are that he will never do a significant experiment. And the more significant and fundamental the experiment the more theoretical uncertainty may be tolerated. By contrast, the more important and difficult the experiment the more that experimental care is warranted. There is no point in attempting a half-hearted experiment with an inadequate apparatus."

"My area of research is something that in all fairness has no practical usability whatsoever and the thing is I'm often asked to apologize for that. It is interesting to me that people ask 'what's the point of doing that if it's not useful?' But they never ask that, or do they very rarely ask that about art or literature or music. Those things are not gonna produce a better toaster."

"There is a maxim about the universe which I always tell my students: That which is not explicitly forbidden is guaranteed to occur."

"Now, since the time of Newton there had been a debate about whether light was a wave---that is, a traveling disturbance in some background medium---or a particle, which travels regardless of the presence of a background medium. The observation of Maxwell that electromagnetic waves must exist and that their speed was identical to that of light ended the debate: light was an electromagnetic wave."

"If you have nothing in quantum mechanics, you will always have something."

"Science simply forces us to revise what is sensible to accommodate the universe, rather than vice versa."

"The other thing people don't realise about science which differentiates it from religion is that, the most exciting thing about being a scientist is not knowing and being wrong. Because that means there is a lot left to learn."

"It is a shame when nonsense can substitute for fact with impunity."

"We only see shadows of reality. We shouldn't expect those shadows to behave sensibly."

"... we're here because of an environmental accident if there is a multiverse and if the laws of physics are different in the different regions ..."

"The amazing thing is that every atom in your body came from a star that exploded, and the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics. You are all stardust. You couldn’t be here if stars hadn’t exploded because the elements—the carbon, nitrogen, oxygen, iron, all the things that matter for evolution—weren’t created at the beginning of time. They were created in the nuclear furnaces of stars, and the only way they could get... into your body is if these stars were kind enough to explode. So, forget Jesus. The stars died so that you could be here today."

"Theorists always know the answer. They're just sometimes right."

"Science is empirical: knowing the answer is nothing. Testing your knowledge means everything."

"The Universe must be flat. Why? Well, there is two reasons. There's the one I normally say, which is: it's the only mathematically beautiful universe. Which is true, but there's another reason I don't usually... talk about but I'll talk about here. It turns out that in a flat universe the total energy of the universe is precisely zero because gravity can have negative energy. So the negative energy of gravity balances out the positive energy of matter. What's so beautiful about a universe with total energy zero? Well, only such a universe can begin from nothing, and that is remarkable because the laws of physics allow a universe to begin from nothing. You don't need a Deity. You have nothing: zero total energy, and quantum fluctuations can produce a universe. So, if the Universe isn't flat we're worried, because then you've got energy at... the very beginning of Time."

"What's going to happen in the far future? Remember a hundred years ago we thought we lived into static eternal Universe. What will the future bring? The amazing thing is, for civilizations that live in a far future, what will they see? Well, the Universe is accelerating. That means all the distant galaxies are getting carried away from us, and eventually they'll move away from us faster than the speed of light. It's allowed in General relativity. They will disappear. The longer we wait, the less we will see. In a hundred billion years any observers evolving on stars around [us]... and there will be stars just like our Sun in 100 billion years. Any observers and civilizations... evolving around those stars will see nothing except for our Galaxy, which is exactly the picture they had in 1915. All evidence of the Hubble expansion will disappear. Why? Because we won't see other galaxies moving apart from us. So they will have no evidence, in fact, of Big Bang. They won't see the Hubble expansion. They won't even know about dark energy, and I won't go into that. They won't know about the cosmic microwave background - it will disappear too. It will redshift away, and it turns out for fancy reasons: there is a plasma in our Galaxy and when the Universe is 50 times its present age the microwave background won't able to propagate in our Galaxy. All evidence of the Big Bang will have disappeared, and those scientists will discover quantum mechanics, discover relativity, discover evolution, discover all the basic principles of science that we understand today, use the best observations they can do with the best telescopes they will build and they will derive a picture of the Universe which is completely wrong. They will derive a picture of the Universe as being one Galaxy surrounded by empty space that's static and eternal. Falsifiable science will produce the wrong answer. In fact, I want to end with the good news. We live in a very special time, the only time we can observationally verify that we live in a very special time."

"Richard Feynman used to go up to people all the time and he'd say, "You won't believe what happened to me today. You won't believe what happened to me." And people would say "What?" And he'd say, "Absolutely nothing". Because we humans believe that everything that happens to us is special, and significant. And that—and... Carl Sagan wrote beautifully about that in Demon-Haunted World—that is much of the source of religion. OK? Everything that happens is unusual, and I expect that the likelihood that Richard and I ever would've met—if you think about all the variables, the probability that we were in the same place at the same time, ate breakfast at the same... Whatever. It's zero. Every event that happens has small probability... but it happens, and then when it happens; if it's weird, if you dream one million nights and it's nonsense, but one night you dream that your friend is gonna break his leg and the next day he breaks his arm. You think, "ah." ...So the [real] thing that physics tell us about the universe is it's big, rare events happen all the time—including life—and that doesn't mean it's special."

"But what we've discovered is that, in fact... the total energy of the universe could be zero, which is a first clue that maybe it could come from nothing. ...In physics, ...once you include gravity, there's positive energy and negative energy, and our universe appears as if its total energy could be precisely zero, which is the first hint that maybe it could come from nothing. That, and the great discovery... that namely empty space, you take a region of space, get rid of all the particles and all the radiation ...so there's nothing there. That empty space weighs something, and we don't understand why."

"The energy of every galaxy—all the galaxies are moving away from us at, Hubble discovered that in 1929... If you measure their speed and then you work our the attraction the two add up to precisely zero. An amazing discovery that confirms this notion that, not only is the universe flat and mathematically beautiful, but begins to give us an inkling that maybe, maybe, maybe we could come from nothing."

"[O]ne of the great things about science is it forces us to refine our idea of what's common sense. It forces us to have our beliefs conform to the evidence of reality rather than the other way around. The universe may not be like we'd like it to be, but it doesn't really care."

"Now some people say, "Well, if there's virtual particles there it's really not nothing," but there are no real particles. You try and measure things there, there's nothing, but those virtual particles can give space energy and in fact we've discovered to our great surprise—it won the Nobel prize two years ago—that empty space has energy, and if you put energy in empty space, then it's really strange because it's not like the normal energy... it's not gravitationally attractive, it's actually repulsive, and we've discovered the expansion of the universe is not slowing down like any sensible universe should do. It's actually speeding up... because it's dominated by the energy of empty space."

"[W]hen you apply quantum mechanics to gravity, then even space itself can pop into existence from nothing. Space and time can spontaneously pop into existence... Whole universes can pop into existence and most of them will disappear in a time scale so short you wouldn't know about it. The ones that can survive for a long time have zero total energy..."

"[Y]ou... may say, "Well look, we've got no space, no time, no particles, no radiation. That's a pretty good approximation of nothing, but there's still the laws. Who created the laws? And... what we've discovered... in the last ten years or so, and... this is speculative, but it's based on everything we know of in particle physics... It's quite reasonable to suspect that even the laws themselves came into existence when our universe came into existence... There could be many different universes and in each one of them the laws of physics are different. They spontaneously arise when the universe arises."

"[W]hy presumes purpose... But what if there isn't purpose? Whenever we say why we really mean how."

"[W]e can weigh systems of galaxies. The largest bound objects in the universe are called clusters of galaxies. They're maybe ten million light years across. ...We weigh them using gravity because Einstein told us that mass curves space, and we can... use those large clusters as lenses—if there's a light source behind a cluster the light from it can come around and be lensed... and we've weighed these systems and we've found that there's only 30% of the mass needed to make a flat universe... Theorists like me knew that the universe was flat, because it's the only mathematically beautiful universe... but here these observers kept coming up with only 30% of the stuff needed... But then, what we've discovered... is that the universe actually is flat and the rest of the 70% of the energy of the flat universe comes from the energy of nothing."

"There's a loophole if you weigh galaxies and clusters because you're weighing the total amount of energy around galaxies. What if there's energy where galaxies aren't? What is where galaxies aren't? Nothing."

"But the very fact that matter in the cosmos is still moving, rather than at rest, is the single most surprising thing about the universe."

"But sometimes reality chooses not to conform to our preferences."

"It can't be stressed enough that the multiverse is utterly hypothetical—but that doesn't mean it isn't real."

"Even if we don't know the answer, a change of perspective can help us improve the question."

"In contrast to the arbitrarily complicated evolution of a (nonintegrable) classical system, all a quantum state ever does is move in circles."

"The mystery of the arrow of time comes down to this: Why were the conditions in the early universe set up in a particular way, in a configuration of low entropy that enabled all of the interesting and irreversible processes to come?"

"Inflation is a simple idea: imagine that the universe begins in a tiny patch of space dominated by the potential energy of some scalar field, a kind of super-dense dark energy. This causes that patch to expand at a terrifically accelerated rate, smoothing out the density and diluting away any unwanted relics. Eventually the scalar field decays into ordinary matter and radiation, reheating the universe into a conventional Big Bang state, after which things proceed as normal."

"There probably are more forces than we know about, but they’re only going to be of direct interest to physicists, I’m afraid. No tractor beams."

"All of my advice comes from remembering what I did wrong and then telling people not to do it. ... Don't wait to read the most recent research papers. ... Wonder how you could do better. ... Do your own research projects. Take the initiative. ... Ask your own questions — try to answer them. ... At some point you stop being a student and you start being a scientist. ... And it's a completely different skill set ...""

"When exactly does an observation occur? ... What were the laws of physics doing before there was anyone measuring things? And what do you mean by a measurement, anyway? Does it have to be a consciousness human being? ... Can a rock or a virus or an earthworm do an observation?"

"People don't like to read papers — they like to read titles."

"... I just want to understand the large-scale story that string gas cosmology is trying to sell us. We have nine dimensions of space — they are all very small — and in three dimensions they start unwinding and getting bigger. Is that the basic idea?"

"The broader ontology typically associated with atheism is naturalism—there is only one world, the natural world, exhibiting patterns we call the “laws of nature,” and which is discoverable by the methods of science and empirical investigation. There is no separate realm of the supernatural, spiritual, or divine; nor is there any cosmic teleology or transcendent purpose inherent in the nature of the universe or in human life. “Life” and “consciousness” do not denote essences distinct from matter; they are ways of talking about phenomena that emerge from the interplay of extraordinarily complex systems. Purpose and meaning in life arise through fundamentally human acts of creation, rather than being derived from anything outside ourselves. Naturalism is a philosophy of unity and patterns, describing all of reality as a seamless web."

"Meaning in life can’t be reduced to simplistic mottos. In some number of years I will be dead; some memory of my time here on Earth may linger, but I won’t be around to savor it."

"Poetic naturalism is a philosophy of freedom and responsibility. The raw materials of life are given to us by the natural world, and we must work to understand them and accept the consequences. The move from description to prescription, from saying what happens to passing judgment on what should happen, is a creative one, a fundamentally human act. The world is just the world, unfolding according to the patterns of nature, free of any judgmental attributes. The world exists; beauty and goodness are things that we bring to it."

"What we’re seeing is a manifestation of the layered nature of our descriptions of reality. At the deepest level we currently know about, the basic notions are things like “spacetime,” “quantum fields,” “equations of motion,” and “interactions.” No causes, whether material, formal, efficient, or final. But there are levels on top of that, where the vocabulary changes."

"The momentary or Laplacian nature of physical evolution doesn’t have much relevance for the choices we face in our everyday lives. For poetic naturalism, the situation is clear. There is one way of talking about the universe that describes it as elementary particles or quantum states, in which Laplace holds sway and what happens next depends only on the state of the system right now."

"Metaphysical principles are tempting shortcuts but not reliable guides. There are good reasons why things often seem to happen for reasons—and also reasons why that’s not a bedrock principle."

"The “reasons” and “causes” why things happen, in other words, aren’t fundamental; they are emergent. We need to dig in to the actual history of the universe to see why these concepts have emerged."

"What we can’t do is demand that the universe scratch our explanatory itches. Curiosity is a virtue, and it’s good to look for answers to “Why?” questions whenever we might be able to find them, or when we think that asking such questions might help us to understand things better. But we should be at peace with the possibility that, for some questions, the answer doesn’t go any deeper than “That’s what it is.” We’re not used to that—our intuition assures us that every event can be explained in terms of some reason why. To understand why we have that impression, we need to dig more deeply into how our actual universe has evolved."

"Equipped with his five senses, man explores the universe around him and calls the adventure Science."

"Science is the one human activity that is truly progressive."

"Eventually, we reach the utmost limits of our telescopes. There, we measure shadows and search among ghostly errors of measurement for landmarks that are scarcely more substantial."

"The history of astronomy is a history of receding horizons."

"...there must be no favored location in the universe, no center, no boundary; all must see the universe alike. And, in order to ensure this situation, the cosmologist postulates spatial isotropy and spatial homogeneity."

"The whole thing is so much bigger than I am, and I can't understand it, so I just trust myself to it; and forget about it."

"We do not know why we are born into the world, but we can try to find out what sort of a world it is — at least in its physical aspects."

"She deserved the Nobel Prize for her work."

"I chucked the law for astronomy, and I knew that even if I were second-rate or third-rate, it was astronomy that mattered."

"If the apparent magnitudes of the nebulae are corrected merely for the effect of the red-shift in diminishing the energy of their observed light, we have seen that Hubble claims that the system is uniformly spread out in space. If, however, the nebulae are receding, an additional dimming factor arises, and the corresponding correction for distance when incorporated in the calculation destroys the homogeneity. Instead, the number of nebulae per unit volume of space now appears to increase as we recede towards the confines of the visible universe. Rightly or wrongly, Hubble maintains that such a picture would imply that we were in a privileged position in the universe, being in the region lease densely populated with nebulae. On these, and other grounds, he is inclined, therefore, to reject the Doppler-interpretation of the red-shifts and to regard the nebulae as stationary."

"Cosmology is a science which has only a few observable facts to work with."

"Hydrogen is a light, odorless gas, which, given enough time, turns into people."

"Why are the heavens not filled with light? Why is the universe plunged into darkness?"

"It is known that very distant nebulae, probably galactic systems like our own, show remarkably high receding velocities whose magnitude increases with the distance. This curious phenomenon promises to provide some important clues for the future development of our cosmological views. It maybe of advantage, therefore, to point out some of the principal facts which any cosmological theory will have to account for. Then a brief discussion will be given of different theoretical suggestions related to the above effect. Finally, a new effect of masses upon light will be suggested which is a sort of gravitational analogue of the Compton effect."

"To eliminate the discrepancy between men's plans and the results achieved, a new approach is necessary. Morphological thinking suggests that this new approach cannot be realized through increased teaching of specialized knowledge. This morphological analysis suggests that the essential fact has been overlooked that every human is potentially a genius. Education and dissemination of knowledge must assume a form which allows each student to absorb whatever develops his own genius, lest he become frustrated. The same outlook applies to the genius of the peoples as a whole."

"I myself can think of a dozen ways to annihilate all living persons within one hour."

"A cluster of galaxies gave the first hints of dark matter (in the modern sense). In 1933, F. Zwicky inferred from measurements of the velocity dispersion in the Coma cluster, a mass-to-light ratio of around 400 solar masses per solar luminoisity, thus exceeding the ratio in the solar neighborhood by two orders of magnitude."

"Zwicky became the darling of reporters everywhere. ... Though the idea of exploding stars may have been floating around, it was Zwicky who made the concepts, and the name supernova, as familiar as relativity. He always had a way with the tart phrase, as well as the boldness necessary to force it into public use, even on the rare occasion, when these attempts failed. His term for black holes—"Objects Hades"—was a much more colorful term that manages to convey both the uniqueness of the objects and the hellish conditions that prevail inside them. Despite his repeated usage, however, that name never caught on. Popular magazines noted his birthday along with those of movie stars. He even made into the funny papers."

"... the Big Bang theory is the accepted theory of cosmology. You never prove anything completely, but it’s the accepted theory of cosmology. And we continue on, in my group, we continue on with balloon observations, and then there’s the and now we’re getting the ready with the , who is sponsoring that. So there’s a whole sequence. What it was, was that was the opening shot and saying OK, there’s some gold to be discovered in the hills, go looking for it."

"But every day I go to work I'm making a bet that the universe is simple, symmetric, and aesthetically pleasing—a universe that we humans, with our limited perspective, will someday understand."

"Absence of evidence is not evidence of absence."

"Once the threshold is crossed when there is a self-sustaining level of life in space, then life's long-range future will be secure irrespective of any of the risks on Earth (with the single exception of the catastrophic destruction of space itself). Will this happen before our technical civilisation disintegrates, leaving this as a might-have-been? Will the self-sustaining space communities be established before a catastrophe sets back the prospect of any such enterprise, perhaps foreclosing it for ever? We live at what could be a defining moment for the cosmos, not just for our Earth."

"We’re all depressingly ‘lay’ outside our specialisms — my own knowledge, of recent biological advances, such as it is, comes largely from ‘popular’ books and journalism."

"No one can say which approach is the right one — so no one can say how close we are to a solution."

"When I discover I'm wrong, I change my mind. What do you do?"

"... I'd want to emphasize that most progress in cosmology and astrophysics has been due to advanced instruments and technology — less than 5 per cent to armchair theory. And I'd expect that balance to continue."

"This is exactly the kind of thing Templeton is ceaselessly angling for – recognition among real scientists – and they use their money shamelessly to satisfy their doomed craving for scientific respectability. They tried it on with the Royal Society of London, and they seem to have found a compliant Quisling in the current President, Martin Rees, who, though not religious himself, is a fervent 'believer in belief'."

"Yes, the universe had a beginning. Yes, the universe continues to evolve. And yes, every one of our body's atoms is traceable to the big bang and to the thermonuclear furnace within high-mass stars. We are not simply in the universe, we are part of it. We are born from it. One might even say we have been empowered by the universe to figure itself out — and we have only just begun."

"A few years ago I got a phone call from a marketing executive who wanted to light up the Moon with the logo of her company. She wanted to know how she might proceed. After slamming down the phone, I called her back and politely explained why it was a bad idea. Other corporate executives have asked me how to put into orbit mile-wide luminous banners with catchy slogans written across them, much like the skywriting or flag-dragging airplanes you see at sports events or over the ocean from a crowded beach. I always threaten to send the light police after them."

"No matter who you are, engaging in the quest to discover where and how things began tends to induce emotional fervor—as if knowing the beginning bestows upon you some form of fellowship with, or perhaps governance over, all that comes later. So what is true for life itself is no less true for the universe: knowing where you came from is no less important than knowing where you are going."

"Cosmologists have plenty of ego — how can a person not be ego-driven when it's your job to deduce what brought the universe into existence? But without data, their explanations were just tall tales. In this modern era of cosmology, each new observation, each morsel of data wields a two-edged sword: it enables cosmology to thrive on the kind of foundation that so much of the rest of science enjoys, but it also constrains theories that people thought up when there wasn't enough data to say whether they were wrong or not. No science achieves maturity without it.Let there be cosmology."

"I don't want students who could make the next major breakthrough in renewable energy sources or space travel to have been taught that anything they don't understand, and that nobody yet understands, is divinely constructed and therefore beyond their intellectual capacity. The day that happens, Americans will just sit in awe of what we don't understand, while we watch the rest of the world boldly go where no mortal has gone before."

"I know that the molecules in my body are traceable to phenomena in the cosmos."

"That makes me want to grab people on the street and say, "have you heard this?""

"People cited violation of the First Amendment when a New Jersey schoolteacher asserted that evolution and the Big Bang are not scientific and that Noah's ark carried dinosaurs. This case is not about the need to separate church and state; it's about the need to separate ignorant, scientifically illiterate people from the ranks of teachers."

"During our brief stay on planet Earth, we owe ourselves and our descendants the opportunity to explore—in part because it's fun to do. But there's a far nobler reason. The day our knowledge of the cosmos ceases to expand, we risk regressing to the childish view that the universe figuratively and literally revolves around us. In that bleak world, arms-bearing, resource-hungry people and nations would be prone to act on their "low contracted prejudices." And that would be the last gasp of human enlightenment—until the rise of a visionary new culture that could once again embrace the cosmic perspective."

"George Bush, within a week of this [the 9/11 attacks], gave us a speech, attempting to distinguish 'we' from 'they' … and how does he do it?.... He says "Our god" — of course it’s actually the same God — but that's a detail, lets hold that minor fact aside for the moment. Allah of the muslims is the same God as the God of the Old Testament so he says … "Our God is the God who named the stars" … Here's the problem with his comment … The problem is: two-thirds of all stars that have names, have Arabic names. I don't think he knew this. That would confound the point that he was making."

"Knowing how things work is important, but I think that's an incomplete view of what science literacy is or, at least, should be. Science literacy is an outlook. It's more of a lens through which you observe what goes on around you."

"Creativity is seeing what everyone else sees, but then thinking a new thought that has never been thought before and expressing it somehow. It could be with art, a sculpture, music or even in science. The difference, however, between scientific creativity and any other kind of creativity, is that no matter how long you wait, no one else will ever compose "Beethoven's Ninth Symphony" except for Beethoven. No matter what you do, no one else will paint Van Gogh's "Starry Night." Only Van Gogh could do that because it came from his creativity.Whereas in science, you can't just make stuff up and presume that it is a proper account of nature. At the end of the day, you have to answer to nature. Since everyone has nature to answer to, your creativity is simply discovering something about the natural world that somebody else would have eventually discovered exactly the same way. They might have come through a different path, but they would have landed in the same place.Even though we name theorems and equations after the people who discover them — Newton's laws of gravity, Kepler's laws of planetary motion — somebody else would have discovered them afterward. It's that simple. Your creativity is not a boundless creativity."

"Some of the most productive times in the histories of nations have been when they were badly stressed — economically, politically, culturally or socially. It's possible to be stressed to a point that more creativity is stimulated than would otherwise be the case. I think it is true that necessity is the mother of invention."

"If you ask adults how many teachers — out of the scores in elementary, middle school, high school, college and graduate school — made a singular impression on who and what they are, it's never more than three or four teachers. Everybody else is a distant second to this set.When we finally create a cloning machine, we should clone those teachers. Maybe that's 100 years from now, but that's at the top of my list. Until that happens, the educational system has not fully understood the causes and effects of achievement and success in life. There remains a culture that equates high grades with success in school and correlates success in school with success in life. That mentality is so deep within us that it may be inextricable from our behavior."

"After your first job, is anyone asking you what your GPA was? No, they don't care. They ask you: Are you a good leader? Do people follow you? Do you have integrity? Are you innovative? Do you solve problems? Somebody's got to do that homework and redesign the educational system so that it can actually train people to be successful in life.I think the greatest teachers are not the ones that are best trained at educational tactics. I don't know a person who's ever said, "Boy, that teacher is so good! The teacher gives such good exams. That teacher gives such good homework sets!" No one has said that about a great teacher. That's not what people remember about the great teachers they've had."

"The best educators are the ones that inspire their students. That inspiration comes from a passion that teachers have for the subject they're teaching. Most commonly, that person spent their lives studying that subject, and they bring an infectious enthusiasm to the audience.I think many people have that enthusiasm, but they are prevented from being teachers because they didn't go through the teacher mill. Now you have teachers who have been through the teacher mill, yet they have no capacity to inspire anyone at all. It's the inspired student that continues to learn on their own. That's what separates the real achievers in the world from those who pedal along, finishing assignments."

"The great tragedy is that they're removing art completely, not because they're putting more science in, but because they can't afford the art teachers or because somebody thinks it's not useful. An enlightened society has all of this going on within it. It's part of what distinguishes what it is to be human from other life forms on Earth — that we have culture."

"I don't know how many people know this, but often it's mindblowing when you learn, that some infinities are bigger than others. [...] The number of counting numbers...so 1, 2, 3, up to infinity...the numbers you would use to count things, that's infinite. The number of irrational numbers...so the numbers you cannot represent as a fraction, okay, there are more of those than there are counting numbers, by far. So these are orders of infinity. Then there are more transcendental numbers than there are irrational numbers. So that's a number you'll never find as a solution to an algebraic equation. So pi is a transcendental number. e is a transcendental number. These are magic numbers that show up in mathematics. And it turns out there's an even bigger infinity of those than there is of these other two classes of numbers. And they use the Hebrew letter aleph in ranking. So it's aleph-1, aleph-2, aleph-3, aleph-4. I think there are five levels of infinity."

"Do parallel universes exist? We don't know, uhm parallel universes are losing favor to the multiverse we have some cogent theoretical expectations that our universe might be just one of many spawned from this, sort of, this hyper-dimensional medium which we'll call the multiverse there's no data to support it but we have good theoretical premise to think that it's there and we have philosophical precedent we used to think Earth was special and unique. It wasn't, we got 8 .. 9 .. 8 planet we thought the Sun was special it's one of a hundred billion suns, the galaxy's special, no there's a hundred billion galaxies we have one universe or do we? The track record said why should there only be one? be open to the possibility that you don't live in the majority [looking?] universe that's out there Would a separate universe .. when you say "different universe" slightly different laws of physics which (that's what I'm asking) oh this is the fun part because if you find, if you manage to get a portal to another universe don't be the first one to volunteer to go through because your atoms are working in this universe if a slightly different law of physics.. you could implode, explode come out with three heads who knows?"

"It has been said that every great emerging scientific truth goes to three phases: First people say: "It can't be true". Second they say: "It conflicts with the bible." Third they say: "It's true all along.""

"I took two bites, bitch!"

"You don't take a dead cat to the vet. I mean you might, but why?"

"Does it mean, if you don’t understand something, and the community of physicists don’t understand it, that means God did it? Is that how you want to play this game? Because if it is, here’s a list of things in the past that the physicists at the time didn’t understand [and now we do understand] [...]. If that’s how you want to invoke your evidence for God, then God is an ever-receding pocket of scientific ignorance that’s getting smaller and smaller and smaller as time moves on - so just be ready for that to happen, if that’s how you want to come at the problem."

"I'm optimistic. I see no longer people accepting fuzzy thinking in the world. The change is not that people aren't still saying under-informed things. The change is that if you're in power and you say something under-informed, there are people out there with a voice who will take you to task for having done so."

"There are people who say "I'll never need this math, these trig identities from 10th grade or 11th grade," or maybe you never learned them. Here's the catch: whether or not you ever again use the math that you learned in school, the act of having learned the math established a wiring in your brain that didn't exist before and it's the wiring in your brain that makes you the problem solver."

"The good thing about science is that it’s true whether or not you believe in it."

"Kids are never the problem. They are born scientists. The problem is always the adults. They beat the curiosity out of the kids. They out-number kids. They vote. They wield resources. That's why my public focus is primarily adults."

"My view is that if your philosophy is not unsettled daily then you are blind to all the universe has to offer."

"Some of the greatest poetry is revealing to the reader the beauty in something that was so simple you had taken it for granted."

"I am trying to convince people--not only the public, but lawmakers and people in power--that investing in the frontier of science, however remote it may seem in its relevance to what you're doing today, is a way of stockpiling the seed corns of future harvests of this nation... Advancing a frontier--history has shown--has advanced a culture ever since the industrial revolution got underway."

"Words that make questions may not be questions at all."

"If you start wielding a hammer, then all your problems look like nails. And maybe they’re not. Maybe it's more subtle than that. And so your toolkit has to be able to morph into what is necessary for what it is that you confront at that moment."

"I could just tell you it's all bunk; but then you wouldn't be empowered to understand why. Other than to quote, "Oh, Doctor Tyson said..." And I never want you to quote me citing my authority as a scientist for your knowing something. If that's what you have to resort to I have failed as an educator. As an educator, it's my duty to empower you to think. So that you can go forth and think accurate thoughts about how the world is put together. Inoculating you against the [people] out there who will exploit your ignorance on anything they possibly can."

"Within one linear centimeter of your lower colon there lives and works more bacteria (about 100 billion) than all humans who have ever been born. Yet many people continue to assert that it is we who are in charge of the world."

"The problem, often not discovered until late in life, is that when you look for things like love, meaning, motivation, it implies they are sitting behind a tree or under a rock. The most successful people recognize, that in life they create their own love, they manufacture their own meaning, they generate their own motivation. For me, I am driven by two main philosophies, know more today about the world than I knew yesterday. And along the way, lessen the suffering of others. You'd be surprised how far that gets you."

"There are street artists. Street musicians. Street actors. But there are no street physicists. A little known secret is that a physicist is one of the most employable people in the marketplace - a physicist is a trained problem solver. How many times have you heard a person in a workplace say, "I wasn't trained for this!" That's an impossible reaction from a physicist, who would say, instead, "Cool. A problem I've never seen before. Let's see how I can figure out how to solve it!" Oh, and, have fun along the way."

"Life is too short for me to worry about something I have no control over that I don’t even know will happen. People ask ‘if Earth is going to be swallowed by a black hole or if there is some disturbance in the spacetime continuum should we worry about it?’. My answer is ‘no’ because you won’t know about it until it crosses your... your place in space-time. Your beats come to you when nature decides it’s the right time... be it the speed of sound, the speed of light, the speed of electrical impulses we will forever be victims of the time delay between information around us and our capacity to receive it."

"What keeps me awake at night: wondering whether human species is just too stupid to figure out the Universe. I just wonder. I lose sleep over that. Because we define ourselves as intelligent— because we made up the test to say that. And we sit alone at the top of the intelligence chart because we invented the exam, and all the other species of life on Earth are not. So who's to say that the first species (us) to be intelligent (us) has just enough intelligence to actually decode everything that's decodable in the Cosmos? [...] Think of the next closest thing to us, the bonobo chimp— 98½% identical DNA, yet you cannot teach them trigonometry, they have no concept of it. So if that's only 1½% difference in our DNA— and so imagine 1½% beyond us, rather than below us, in intelligence. [...] Their toddlers would be talking about things that would completely confound us."

"What is NASA's mission? Is it to beat the russians? Is it to inspire?"

"If you want to assert a truth, first make sure it's not just an opinion that you desperately want to be true."

"All I can say is, the universe is in a good shape, it's earth that has all the problems."

"As important as Steve Jobs was, no doubt about it — [and] you have to add him to Bill Gates, because they birthed the personal computing revolution kind of together — here's the difference: Elon Musk is trying to invent a future, not by providing the next app."

"The universe is under no obligation to make sense to you."

"Ignorance is the natural state of mind for a research scientist. People who believe they are ignorant of nothing have neither looked for, nor stumbled upon, the boundary between what is known and unknown in the universe. What we do know, and what we can assert without further hesitation, is that the universe had a beginning. The universe continues to evolve. And yes, every one of our body’s atoms is traceable to the big bang and to the thermonuclear furnaces within high-mass stars that exploded more than five billion years ago. We are stardust brought to life, then empowered by the universe to figure itself out—and we have only just begun."

"This universality of physical laws drives scientific discovery like nothing else."

"To the scientist, the universality of physical laws makes the cosmos a marvelously simple place. By comparison, human nature—the psychologist’s domain—is infinitely more daunting. In America, local school boards vote on subjects to be taught in the classroom. In some cases, votes are cast according to the whims of cultural, political, or religious tides. Around the world, varying belief systems lead to political differences that are not always resolved peacefully. The power and beauty of physical laws is that they apply everywhere, whether or not you choose to believe in them. In other words, after the laws of physics, everything else is opinion."

"Cosmologists have plenty of ego. How could you not when your job is to deduce what brought the universe into existence?"

"In our own solar system, for example, everything that is not the Sun adds up to less than one fifth of one percent of the Sun’s mass."

"Other unrelenting skeptics might declare that “seeing is believing”—an approach to life that works well in many endeavors, including mechanical engineering, fishing, and perhaps dating. It’s also good, apparently, for residents of Missouri. But it doesn’t make for good science. Science is not just about seeing, it’s about measuring, preferably with something that’s not your own eyes, which are inextricably conjoined with the baggage of your brain. That baggage is more often than not a satchel of preconceived ideas, post-conceived notions, and outright bias."

"Personally, I am quite comfortable with chemicals, anywhere in the universe. My favorite stars, as well as my best friends, are all made of them."

"Of all the sciences cultivated by mankind, Astronomy is acknowledged to be, and undoubtedly is, the most sublime, the most interesting, and the most useful. For, by knowledge derived from this science, not only the bulk of the Earth is discovered . . . ; but our very faculties are enlarged with the grandeur of the ideas it conveys, our minds exalted above [their] low contracted prejudices."

"When I pore over the data that establish the mysterious presence of dark matter and dark energy throughout the universe, sometimes I forget that every day—every twenty-four-hour rotation of Earth—people kill and get killed in the name of someone else’s conception of God, and that some people who do not kill in the name of God, kill in the name of needs or wants of political dogma."

"Within a month of opening day, I received a letter from an Ivy League professor of psychology whose expertise was in things that make people feel insignificant…He wanted to administer a before-and-after questionnaire to visitors, assessing the depth of their depression after viewing the show. Passport to the Universe, he wrote, elicited the most dramatic feelings of smallness and insignificance he had ever experienced. How could that be? Every time I see the space show (and others we’ve produced), I feel alive and spirited and connected. I also feel large, knowing that the goings-on within the three-pound human brain are what enabled us to figure out our place in the universe. Allow me to suggest that it’s the professor, not I, who has misread nature. His ego was unjustifiably big to begin with, inflated by delusions of significance and fed by cultural assumptions that human beings are more important than everything else in the universe. In all fairness to the fellow, powerful forces in society leave most of us susceptible. As was I, until the day I learned in biology class that more bacteria live and work in one centimeter of my colon, than the number of people who have ever existed in the world. That kind of information makes you think twice about who–or what–is actually in charge. From that day on, I began to think of people not as the masters of space and time but as participants in a great cosmic chain of being, with a direct genetic link across species both living and extinct, extending back nearly four billion years to the earliest single-celled organisms on Earth."

"If a huge genetic gap separated us from our closest relative in the animal kingdom, we could justifiably celebrate our brilliance. We might be entitled to walk around thinking we’re distant and distinct from our fellow creatures. But no such gap exists. Instead, we are one with the rest of nature, fitting neither above nor below, but within."

"The cosmic perspective flows from fundamental knowledge. But it’s more than about what you know. It’s also about having the wisdom and insight to apply that knowledge to assessing our place in the universe. And its attributes are clear: The cosmic perspective comes from the frontiers of science, yet it is not solely the provenance of the scientist. It belongs to everyone. The cosmic perspective is humble. The cosmic perspective is spiritual—even redemptive—but not religious. The cosmic perspective enables us to grasp, in the same thought, the large and the small. The cosmic perspective opens our minds to extraordinary ideas but does not leave them so open that our brains spill out, making us susceptible to believing anything we’re told. The cosmic perspective opens our eyes to the universe, not as a benevolent cradle designed to nurture life but as a cold, lonely, hazardous place, forcing us to reassess the value of all humans to one another. The cosmic perspective shows Earth to be a mote. But it’s a precious mote and, for the moment, it’s the only home we have. The cosmic perspective finds beauty in the images of planets, moons, stars, and nebulae, but also celebrates the laws of physics that shape them. The cosmic perspective enables us to see beyond our circumstances, allowing us to transcend the primal search for food, shelter, and a mate. The cosmic perspective reminds us that in space, where there is no air, a flag will not wave, an indication that perhaps flag-waving and space exploration do not mix. The cosmic perspective not only embraces our genetic kinship with all life on Earth but also values our chemical kinship with any yet-to-be discovered life in the universe, as well as our atomic kinship with the universe itself."

"At least once a week, if not once a day, we might each ponder what cosmic truths lie undiscovered before us, perhaps awaiting the arrival of a clever thinker, an ingenious experiment, or an innovative space mission to reveal them. We might further ponder how those discoveries may one day transform life on Earth. Absent such curiosity, we are no different from the provincial farmer who expresses no need to venture beyond the county line, because his forty acres meet all his needs. Yet if all our predecessors had felt that way, the farmer would instead be a cave dweller, chasing down his dinner with a stick and a rock."

"in Space where there ain't no gravity, helicopter dick really do be a way to travel."

"... the anatomy of a sound bite is—it's gotta be interesting. And it's gotta be tasty. It should also be a little bit fun to hear ... so that you smile. And it's gotta have enough of all that to want to tell someone else that you just learned something. ... I have a master class on thinking like a scientist and how to communicate what you know in your expertise to others."

"Science is a cooperative enterprise spanning the generations. It's the passing of a torch from teacher to student to teacher; a community of minds reaching back to antiquity and forward to the stars. (From the first Cosmos: ASO episode, Standing Up in the Milky Way.)"

"The Theory of Evolution, like the Theory of Gravity, is a scientific fact. Evolution really happened. Accepting our kinship with all life on earth is not only solid science, in my view, it's also a soaring spiritual experience. (From the second Cosmos: ASO episode, Some of the Things That Molecules Do.)"

"Halley shattered their monopoly, beating them at their own game. A game that no scientist had ever played before: Prophecy. -S01E03"

"Ibn al-Haytham was the first person ever to set down the rules of science. -S01E05"

"In this moment, I am euphoric. Not because of any phony god’s blessing. But because, I am enlightened by my intelligence"

"he does have that same passion to connect that is critical if you want to be a science communicator."

"Could it be, nevertheless, that Einstein's theory is wrong? Might it be necessary to modify it—to find a new theory of gravity that can explain both the stronger gravity and the apparent antigravity being observed today—rather than simply throwing in invisible things to make the standard model work?"

"Almost 30 percent of the total matter-energy budget is said to be composed of so-called cold dark matter and almost 70 percent of "dark energy," leaving only about 4 percent as visible matter in the form of the atoms that make up the stars, planets, interstellar dust, and ourselves. Such is the degree of discrepancy between theory and observations today."

"When I was a student at Trinity College, Cambridge, in the 1950s, Sir Isaac Newton's presence was still almost palpable."

"Einstein entertained counterintuitive notions that allowed him to pull physics from the mechanistic, clockwork universe of the eighteenth century up into the twentieth century."

"The eighteenth-century German philosopher Immanuel Kant had conjectured that Messier's nebulae were distant "island universes" outside our Milky Way galaxy, but many scientists in the early twentieth century disagreed."

"Today, like the elusive planet Vulcan in the nineteenth century, dark matter is accepted by the majority of astronomers and physicists as actually existing. Dark matter, although it has never been seen, is part of the generally accepted standard model of physics and cosmology, which also includes the big bang beginning of the universe."

"Hunting for elusive dark matter is now a multibillion dollar international scientific industry."

"It may be that ultimately the search for dark matter will turn out to be the most expensive and largest null result experiment since the Michelson-Morely experiment, which failed to detect the ether."

"It is hard to understand how this infinitely dense singularity can evaporate into nothing. For matter inside the black hole leak out into the universe requires that it travel faster than the speed of light."

"Is the reader feeling confused about the status of the black hole information paradox and black holes in general? So am I!"

"Experimentalists dream of some spectacular discovery such as the proof of the existence of black holes to justify the more than eight billion dollars it has cost to build the LHC."

"A much faster speed of light in the infant universe solved the horizon problem and therefore explained the overall smoothness of the temperatures of the CMB radiation, because light now traveled extremely quickly between all parts of the expanding but not inflating universe."

"Inflation itself proceeds at a speed faster than the measured speed of light."

"In estimating the amount of dark matter, cosmologists developing the standard model have to make some rather strong assumptions about their observations."

"One truth we have been able to count on concerning scientific persuit over the centuries has been that only testable theories survive the intense scrutiny of experimental science."

"To physicists such as myself, the huge amount of invisible dark matter needed to make Einstein's theory fit the astrophysical data is reason enough for exploring modified gravity theories."

"It is difficult to falsify the hypothesis of dark matter, because, as with Ptolemy's epicycles, true believers can always add additional arbitrary features and free parameters to overcome any conceivable difficulties that occur with the dark matter models."

"A large part of the relativity community is in denial - refusing even to contemplate the idea that black holes may not exist in nature, or seriously consider the idea that any kind of new matter such as the new putative dark energy can play a fundamental role in gravity theory."

"This is the only sure way I know to counter the anti-Copernican idea that the universe is accelerating in our epoch - to get rid of the problem entirely!"

"Indeed, there is a now a minority of cosmologists who question a beginning of the universe at all; instead they favor a cyclic model with a series of expansions and contractions."

"This is an extraordinary time in the history of science, in that we cannot only theorize about the beginning of the universe, but actually study the celestial fossils of how it happened."

"Giving up Einstein's theory of gravity is simply unacceptable to many in the community. It may take a new generation of physicists to view the evidence with unclouded eyes."

"Neither in any if the stars, nor in the sun, nor in the planets that are most operant in the world, can organs be disntinguished or imagined by us; nevertheless, they live and endow with life small bodies at the earth's elevated points. If there is aught of which man may boast, that of a surety is soul, is mind; and the other animals, too, are ennobled by soul; even God, by whose rod all things are governed, is soul."

"Only on the superficies of the globes is plainly seen the host of souls and of animate existences, and their great and delightful diversity the Creator taketh pleasure"

"We, therefore, having directed our inquiry toward a cause that is manifest, sensible, and comprehended by all men, do know that the earth rotates on its own poles, proved by many magnetical demonstrations to exist. For not in virtue only of its stability and its fixed permanent position does the earth possess poles and verticity; it might have had another direction, as eastward or westward, or toward any other quarter. By the wonderful wisdom of the Creator, therefore, forces were implanted in the earth, forces primarily animate, to the end the globe might, with steadfastness, take direction, and that the poles might be opposite, so that on them, as at the extremities of an axis, the movement of diurnal rotation might be performed."

"The electric effluvia differ much from air, and as air is the earth's effluvium, so electric bodies have their own distinctive effluvia; and each peculiar effluvium has its own individual power of leading to union, its own movement to its origin, to its fount, and to the body emitting the effluvium."

"Lucid gems are made of water; just as Crystal, which has been concreted from clear water, not always by a very great cold, as some used to judge, and by very hard frost, but sometimes by a less severe one, the nature of the soil fashioning it, the humour or juices being shut up in definite cavities, in the way in which spars are produced in mines."

"How far away from the earth are those remotest of stars: they are beyond the reach of eye, or man's devices, or man's thought. What an absurdity is this motion (of spheres). He also argues for the extreme variability of the distance to the various heavenly bodies and states that situated "in thinnest aether, or in the most subtle fifth essence, or in vacuity - how shall the stars keep their places in the mighty swirl of these enormous spheres composed of a substance of which no one knows aught?"

"In the discovery of hidden things and in the investigation of hidden causes, stronger reasons are obtained from sure experiments and demonstrated arguments than from probable conjectures and the opinions of philosophical speculators of the common sort."

"The Alchemists have made a philosophy out of a few experiments of the furnace and Gilbert our countryman hath made a philosophy out of observations of the lodestone."

"[Gilbert] has himself become a magnet; that is, he has ascribed too many things to that force and built a ship out of a shell."

"Gilbert shall live till loadstones cease to draw, Or British fleets the boundless ocean awe."

"Gilbert... repeatedly asserts the paramount value of experiments. He himself, no doubt, acted up to his own precepts; for his work contains all the fundamental facts of the science [of magnetism], so fully examined, indeed, that even at this day we have little to add to them."

"Gilbert, in his work, De Magnete printed in 1600 has only some vague notions that the magnetic virtue of the earth in some way determines the direction of the earth's axis, the rate of its diurnal rotation, and that of the revolution of the moon about it. Gilbert died in 1603, and in his posthumous work (De Mundo nostro Sublunari Philosophia nova, 1631) we have already a more distinct statement of the attraction of one body by another. "The force which emanates from the moon reaches to the earth, and, in like manner, the magnetic virtue of the earth pervades the region of the moon: both correspond and conspire by the joint action of both, according to a proportion and conformity of motions, but the earth has more effect in consequence of its superior mass; the earth attracts and repels, the moon, and the moon within certain limits, the earth; not so as to make the bodies come together, as magnetic bodies do, but so that they may go on in a continuous course." Though this phraseology is capable of representing a good deal of the truth, it does not appear to have been connected... with any very definite notions of mechanical action in detail."

"The year 1600 was the first in which England produced a remarkable work in physical science; but this was one sufficient to raise a lasting reputation to its author. Gilbert, a physician, in his Latin treatise on the magnet, not only collected all the knowledge which others had possessed on that subject, but became at once the father of experimental philosophy in this island, and by a singular felicity and acuteness of genius, the founder of theories which have been revived after the lapse of ages, and are almost universally received into the creed of the science. The magnetism of the earth itself, his own original hypothesis... was by no means one of those vague conjectures... He relied on the analogy of terrestrial phenomena to those exhibited by what he calls a terrella, or artificial spherical magnet. ...Gilbert was also one of our earliest Copernicans, at least as to the rotation of the earth; and with his usual sagacity inferred, before the invention of the telescope, that there are a multitude of fixed stars beyond the reach of our vision."

"The "New Philosophy" [De Mundo Nostro Sublunari Philosophia Nova] of Gilbert came to be published half a century after his death in the following curious circumstances. Within the period of apparently some two years after his demise, William Gilbert, of Melford, his elder brother, bearing, oddly enough, the same name... found, among Gilbert's scattered papers, the fragmentary New Philosophy and the Meteorology. These (as he says, being governed by fraternal affection, as well as by an appreciation of the importance of the arguments advanced, whereof he felt unwilling to deprive the world), he arranged, caused to be translated into Latin, and prefixed to them a dedication... That he intended to publish the book is clear; nevertheless, he departed, as its author had done with his purpose unfulfilled."

"In 1626 Bacon succumbed to the results of his ill timed experiment in preserving chickens with snow... The Bacon manuscripts were sent to [Sir William] Boswell's residence at the Hague, and there lay until Boswell, who died in 1647, confided them to the editorial care of Isaac Gruter who... published them all together in 1653. Among the papers which thus came into his hands, Gruter found the two manuscripts of William Gilbert, of Colchester, which William Gilbert, of Melford, had prepared, and these he edited and issued... in 1651."

"The significant fact lies in the possession of the manuscripts by Bacon during his lifetime. He studied them, he knew their contents. And in those great Monuments wherein he has invoked for his own fame the judgment of the next age, he attacks and condemns over and over again the opinions of a man who could neither speak for himself, being in his grave, nor be spoken for by the only written words wherein he had set them forth, and which in the cabinet of my Lord Verulam, were as effectually silenced and entombed."

"The famous treatise which opened the modern era by treating magnetism and electricity on a scientific basis appeared just 300 years ago. The author, William Gilbert, M.D., of Colchester... was an exact and diligent explorer, first of chemical and then of magnetic and electric phenomena. ...Working nearly a century before the time when the astronomical discoveries of Newton had originated the idea of attraction at a distance, he established a complete formulation of the interaction of magnets by what we now call the exploration of their fields of force. His analysis of the facts of magnetic influence, and incidentally of the points in which it differs from electric influence, is virtually the one which Faraday reintroduced. A cardinal advance was achieved, at a time when the Copernican Astronomy had still largely to make its way, by assigning the behavior of the compass and the dip needle to the fact that the earth itself is a great magnet, by whose field of influence they are controlled. His book passed through many editions on the Continent within forty years; it won the high praise of Galileo. Gilbert has been called the 'father of modern electricity' by Priestley, and 'the Galileo of magnetism' by Poggendorff."

"Gilbert does not seem to have known that there were any other bodies than iron or the lodestone that possessed magnetic properties; for he called particular attention to the fact that all other substances that possessed magnetism to some degree owe their power to the presence of iron in some condition or other."

"When Gilbert of Colchester, in his “New Philosophy,” founded on his researches in magnetism, was dealing with tides, he did not suggest that the moon attracted the water, but that “subterranean spirits and humors, rising in sympathy with the moon, cause the sea also to rise and flow to the shores and up rivers”. It appears that an idea, presented in some such way as this, was more readily received than a plain statement. This so-called philosophical method was, in fact, very generally applied, and Kepler, who shared Galileo’s admiration for Gilbert’s work, adopted it in his own attempt to extend the idea of magnetic attraction to the planets."

"William Gilbert of Colchester, Physician of London: On the Load Stone and Magnetic Bodies by William Gilbert, Edward Wright; J. Wiley & Sons (1893) public domain @GoogleBooks."

"The Big Bang theory has been extremely successful in describing the history and evolution of the Universe, and new experiments and observations continue to confirm the basic predictions of this theory. But we do not yet know the answer to the question"

"Neutrinos are fundamental subatomic particles produced in nuclear reactions, like those in the sun. We always talk about the fact that we can’t see neutrinos or dark matter and that basically they’re invisible, but if you think about it from the other side, we’re also invisible to them."

"Nothing in nature or the cosmos is ever completely still — as I write this, several wild Mallards have returned to the Museum courtyard and are creating a frantic spectacle of water and wings as they dive and attack in their annual spring ritual. Further from home, a supermassive black hole at the center of a galaxy 56 million light years from Earth has recently been observed to be spinning at close to the speed of light."

"On the most usual assumption, the universe is homogeneous on the large scale, i. e. down to regions containing each an appreciable number of nebulae. The homogeneity assumption may then be put in the form: An observer situated in a nebula and moving with the nebula will observe the same properties of the universe as any other similarly situated observer at any time."

"The kind of lecture which I have been so kindly invited to give, and which now appears in book form, gives one a rare opportunity to allow the bees in one's bonnet to buzz even more noisily than usual."

"All science is full of statements where you put the best face on your ignorance, where you say: true enough, we know awfully little about this, but more or less irrespective of the stuff we don't know about, we can make certain useful deductions."

"Time is that which is measured by a clock. This is a sound way of looking at things. A quantity like time, or any other physical measurement, does not exist in a completely abstract way. We find no sense in talking about something unless we specify how we measure it. It is the definition by the method of measuring a quantity that is the one sure way of avoiding talking nonsense about this kind of thing."

"The landscape has been so totally changed, the ways of thinking have been so deeply affected, that it is very hard to get hold of what it was like before... It is very hard to realize how total a change in outlook Isaac Newton has produced."

"Is the flow of time something real, or might our sense of time passing be just an illusion that hides the fact that what is real is only a vast collection of memories?"

"The five big questions in physics 1. How to unify quantum theory and gravity? 2. Does quantum mechanics really make sense? 3. Unify the different forces and particles 4. What sets the masses of the particles? 5. What are the dark matter and energy?"

"Rule I: Except during a measurement, the wave evolves smoothly and deterministically, like a wave on water. ... Rule II: During a measurement of position, the wave collapses around the position where it is seen, with a probability proportional to the square of the height of the wave, before the collapse. ... In fact the two rules seem to contradict each other."

"Since the 1960s, particle theory had been split into two groups: those following the atomism of the quark theory and those who had followed the anti-atomism of that had led from the bootstrap program to the string theory. What happened in 1984 was that it was realised that string theory could combine and satisfy the aspirations of both approaches to fundamental physics. Thus, the community of gauge theorists, driven by the failure of the proton decay experiments to search for new ideas that could unify physics, all of a sudden encountered their old friends, the string theorists, in the middle of what might be called a desert of disappointed expectations."

"The first principle of cosmology must be 'There is nothing outside the universe'. This is not to exclude religion or mysticism... But if it is knowledge that we desire... we need to seek answers to questions about the things we can see... only things that exist in the universe."

"There is no meaning to space that is independent of the relationships among real things of the world. ...Space is nothing apart from the things that exist. ...If we take out all the words we are not left with an empty sentence, we are left with nothing."

"The geometry of space changes when things in the universe change their relationships to one another."

"There are unfortunately not a few good professional physicists who still think about the world as if space and time had an absolute meaning."

"I believe that the main lesson of relativity and quantum theory is that the world is nothing but an evolving network of relationships."

"The relational picture of space and time has implications that are as radical as those of natural selection, not only for science but for our perspective on who we are and how we came to exist in this evolving universe of relations."

"We are the result of processes much more complicated than the small aspects of our lives and societies over which we have some control."

"There is no fixed, eternal frame to the universe to define what may or may not exist."

"There is nothing beyond the world except what we see, no background to it except its particular history."

"We have known since the middle of the nineteenth century that the world is not composed only of particles. ...the world is also composed of fields. ...General relativity is a theory of... the gravitational field. ...Because there are three sets of field lines, the gravitational field defines a network of relationships having to do with how the... lines link with one another. ...This is why we call relativity a relational theory."

"In the theory of electric fields it is assumed that points have meaning. ...Physicists using general relativity... cannot speak of a point, except by naming some features of the field lines that will uniquely distinguish that point. ...the network of relationships evolve with time... constantly changing."

"There is no time apart from change. There is no such thing as a clock outside the network of changing relationships. ...one can only compare how fast one thing is happening with the rate of some other process."

"Time is described only in terms of change in the network of relationships that describes space."

"It is absurd in general relativity to speak of a universe in which nothing happens."

"Neither space nor time has any existence outside the system of evolving relationships that comprises the universe. Physicists refer to this feature of general relativity as background independence."

"In quantum theory, distance is inverse to energy, because you need particles of very high energy to probe very short distances. The inverse of the Planck energy is the Planck length."

"We detect light and particles that have traveled billions of light years on their way across the universe to us. During the billions of years of travel, very small effects due to quantum gravity can be amplified to the point that we can detect them."

"Since the 1950s, the key equation of quantum gravity has been called the Wheeler-DeWitt equation. Bryce DeWitt and John Wheeler wrote it down, but in all the time since then, no one had been able to solve it. We found we could solve it exactly, and in fact we found an infinite number of exact solutions."

"I was joined by Carlo Rovelli, and we were able to make a full-fledged quantum theory of gravity... This became loop quantum gravity."

"While most people... were seeking to modify the principles of either relativity or quantum theory, we surprised ourselves (and many other people) by succeeding in putting them together without modifying their principles."

"There is a smallest unit of space. Its minimum value is given by the cube of the Planck length... If you take a volume of space and measure it to a very fine precision... It has to fall into some discrete series of numbers, just like the energy of an electron in an atom. ...we can calculate the discrete areas and volumes from the theory."

"Some of the effects predicted by the theory [of loop quantum gravity] appear to be in conflict with one of the principles of Einstein's special theory of relativity... that the speed of light is a universal constant. ...Photons of higher energy travel slightly slower than low-energy photons. ...the principle of [general] relativity is preserved but Einstein's special theory of relativity requires modification. ...A photon can have an energy-dependent speed without violating the principle of [general] relativity!"

"Jacob Bekenstein found... in 1971 that every black hole must have an entropy proportional to the area of its horizon... Stephen Hawking then refined this by showing that the constant of proportionality must be... exactly one quarter. ...entropy is supposed to correspond to a measure of information ...Loop quantum gravity... [gives] a detailed description of the microscopic structure of a black hole. ...a horizon can have, for each quantized unit of area, a finite number of states. Counting them, we get exactly Bekenstein's result..."

"Spacetime... turns out to be discrete, described by a structure called spin foam."

"In string theory one studies strings moving in a fixed classical spacetime. ...what we call a background-dependent approach. ...One of the fundamental discoveries of Einstein is that there is no fixed background. The very geometry of space and time is a dynamical system that evolves in time. The experimental observations that energy leaks from binary pulsars in the form of gravitational waves—at the rate predicted by general relativity to the... accuracy of eleven decimal places—tell us that there is no more a fixed background of spacetime geometry than there are fixed crystal spheres holding the planets up."

"String theory seems to be incompatible with a world in which a cosmological constant has a positive sign, which is what the observations indicate."

"From the beginning of physics, there have been those who imagined they would be the last generation to face the unknown. Physics has always seemed to its practitioners to be almost complete. This complacency is shattered only during revolutions, when honest people are forced to admit that they don't know the basics."

"Relativity and... quantum... remain incomplete. ...the main reason each is incomplete is the existence of the other. The mind calls for a third theory to unify all of physics, and for a simple reason. Nature is... "unified." …interconnected, in that everything interacts with everything else."

"Combine general relativity and quantum theory into a single theory that can claim to be the complete theory of nature. This is called the problem of quantum gravity."

"In both quantum theory and general relativity, we encounter predictions of physically sensible quantities becoming infinite. This is likely the way that nature punishes impudent theorists who dare to break her unity. ...If infinities are signs of missing unification, a unified theory will have none. It will be what we call a finite theory."

"Quantum theory can be described as a new kind of language to be used in a dialogue between us and the systems we study with our instruments. ...It tells us nothing about what the world would be like in our absence."

"Many of the founders of quantum mechanics, including Einstein, Erwin Schrödinger, and Louis de Broglie... were realists. For them quantum theory... was not a complete theory, because it did not provide a picture of reality absent our interaction with it. On the other side were Niels Bohr, Werner Heisenberg, and many others. Rather than being appalled, they embraced this new way of doing science."

"Many of us believed in the possibility of a principled explanation for the laws of nature. We hoped to discover a short list of principles, which could be realized in a unique theory, which would retrodict the standard model and uniquely predict the physics to be discovered beyond it. The shocking implication of the results of Strominger reported in 1986 was that it was not to be, at least within the confines of string theory. ...String theory offered more, however... It offered the promise of a setting in which the different perturbative string theories are realized as expansions around solutions of a still more fundamental theory. ...That more fundamental theory would have to be background independent..."

"Unfortunately, so far... a truly background independent formulation of string theory has not been achieved... [It is] often called the search for M theory..."

"The landscape problem and the problem of background independence are closely linked. The latter is the only route the former has to experimental confirmation."

"The hypothesis underlying all approaches to the landscape is that there is a cosmological setting in which different regions or epochs of the universe can have different effective laws. This implies the existence of spacetime regions not directly observable... These regions must either be in the past of our big bang, or far enough away from us to be causally unrelated."

"The landscape problem represents a serious problem in the development of science. Its solution requires... the construction of speculative cosmological scenarios, which posit regions or epochs of our universe for which we presently have no observable evidence. Nonetheless we must insist on taking seriously only scenarios and hypotheses that make falsifiable or strongly verifiable predictions, otherwise people can just make stuff up and the distinction between science and mythology becomes porous. ...there are already candidate solutions that make real, falsifiable predictions."

"Special pleading that the standards of science should be lessened to admit explanations with no falsifiable consequences, in order to keep alive a bold speculative idea, should be strongly resisted. ...ultimately science is not interested in what might be true, it is interested only in what can be convincingly demonstrated by deductions from observational evidence."

"Having begun my life in science searching for the equation beyond time, I now believe that the deepest secret of the universe is that its essence rests in how it unfolds moment by moment in time."

"We seem to have an ingrained idea that if something is valuable, it exists outside of time."

"I... propose that time and its passage are fundamental and real and the hopes and beliefs about timeless truths and timeless realms are mythology."

"If we believe that the task of physics is the discovery of a timeless mathematical equation that captures every aspect of the universe, then we believe that the truth about the universe lies outside the universe."

"Thinking in time is not relativism but a form of relationalism... the truest description of something consists of specifying its relationships to other parts of the system it is part of."

"To be human is to be suspended between danger and opportunity. ...The challenge of life is to choose wisely, from the enormous number of possible dangers, what's worth worrying about. It is also about choosing, from all the opportunities... always in the face of incomplete knowledge of the consequences."

"One of the evident facts about the world is the stability of empty space-time. In classical general relativity we can explain this as a consequence of the positive energy theorem... the positive energy theorem must extend in some suitable form to any viable quantum theory of gravity."

"We show that some known classical results have particularly simple derivations within the Ashtekar formalism. These include Witten's positive energy theorem..."

"The positive energy theorem was for half a century or more an open challenge to relativists. Many attempts were made to prove flat spacetime was stable, but none completely succeeded completely until a majestic tour de force of geometric reasoning of Shoen and Yau. This was followed two years later by a proof of Witten, which was as elegant as it was short. It is this proof of Witten’s that we take as a template here for the quantum theory."

"The suggestion was that a positive energy proof for general relativity could be gotten by restricting supergravity to its bosonic sector, which is general relativity."

"Calculation establishes that a quantum positive energy theorem may be possible using a representation based on the Ashtekar connection. Left open is a key question of whether this use of the Ashtekar connection is necessary or whether a positive quantum energy result can be achieved for representations based on other connections, i.e., for [other] values of the Immirzi parameter."

"To explain the appearance in MOND of a cosmological acceleration constant, a0, I suggest that MOND inertia — as embodied in the actions of free particles and fields — is due to effects of the vacuum. The same vacuum effects enter both MOND (through a0) and cosmology e.g. through a cosmological constant Λ)."

"It seems to me that in understanding MOND and its fundamentals we have only scratched the surface. If the developments of quantum mechanics and relativity are any lesson here, departures of such magnitude from long- and well-tested physics may bring with them completely new concepts, not summarized by mere modifications of the governing actions or the equations of motion. MOND may also turn out to bring in concepts that are presently beyond our ken (as hinted perhaps by the cosmological connotations of a0)."

"Dark matter cannot be any sort of matter that is known to science."

"Of all of the many mysteries of modern astronomy, none is more vexing than the nature of dark matter... This dark matter has eluded every effort by astronomers and physicists to bring it out of the shadows. A handful of us suspect that it might not really exist, and others are beginning to consider this possibility seriously."

"What makes MOND particularly intriguing is that it predicted many effects that could not even be tested when I formulated it."

"I did encounter much opposition and sheer disregard, and this was against my expectation. I was surprised that people thought that this was not a legitimate avenue to explore. Many times I heard people say that it is too early to start considering such heretical ideas. Why? I wondered. I thought it was legitimate to consider anything."

"The nice thing is that MOND has not had to change or adjust itself to the many observations that came after it was proposed. … In the end, the process that might sway people's minds could be a slow one, in which they become disillusioned and dissatisfied with DM, while MOND explains more and more of the observations. And, if MOND does turn out to have some truth to it, the fact that it encountered so much opposition will just show how nontrivial a thought it was."

"What struck me was some regularity in the anomaly. The rotational velocities were not just larger than expected, they became constant with radius. Why? Sure, if there was dark matter, the speed of stars would be greater, but the rotation curves, meaning the rotational speed drawn as a function of the radius, could still go up and down depending on its distribution. But they didn't. That really struck me as odd. So, in 1980, I went on my Sabbatical in the Institute for Advance Studies in Princeton with the following hunch: If the rotational speeds are constant, then perhaps we’re looking at a new law of nature. If Newtonian physics can’t predict the fixed curves, perhaps we should fix Newton, instead of making up a whole new class of matter just to fit our measurements."

"I've never observed wisdom to emerge from shouting."

"You can lead a theorist to data, but you can't make him think."

"Obvious results provoke opposition. The more obvious the result, the stronger the opposition."

"It is often stated that the evidence for is overwhelming. This is not quite correct: the evidence for mass discrepancies is overwhelming. These might be attributed to either dark matter or a modification of gravity."

"My gut reaction to all these questions is negative. But it appears that one set or the other must be answered in the affirmative. Either way, we are missing something fundamental about the nature of our universe."

"I came to the subject a True Believer in dark matter, but it was MOND that nailed the predictions for the LSB galaxies that I was studying (McGaugh & de Blok, 1998), not any flavor of dark matter. So what I am supposed to conclude?"

"One should not only be truthful, but as complete as possible. It does not suffice to be truthful while leaving unpleasant or unpopular facts unsaid."

"A long standing prediction (Milgrom 1983) of MOND is that rotating galaxy curves will fall on a single mass-velocity relation with slope 4: Mb \propto Vf4. This prediction is realized in multiple independent data sets. Gas rich galaxies fall where predicted by MOND with no free parameters. There are not many predictions in extragalactic astronomy that fare so well a quarter century after their publication. … a physical understanding for why galaxy formation in the context of ΛCDM should pick out the particular phenomenology predicted a priori by MOND remains wanting."

"The current cosmological paradigm, the cold dark matter model with a cosmological constant, requires that the mass-energy of the Universe be dominated by invisible components: dark matter and dark energy. An alternative to these dark components is that the law of gravity be modified on the relevant scales. A test of these ideas is provided by the baryonic Tully-Fisher relation (BTFR), an empirical relation between the observed mass of a galaxy and its rotation velocity. Here, I report a test using gas rich galaxies for which both axes of the BTFR can be measured independently of the theories being tested and without the systematic uncertainty in stellar mass that affects the same test with star dominated spirals. The data fall precisely where predicted a priori by the modified Newtonian dynamics."

"... It was (in part) Gross’s excessive enthusiasm for string theory in the mid-80s that drove me (as an impressionable grad student at Princeton) away from theoretical physics (and into astronomy). String theory may have been a beautiful idea, but it made no predictions that could be tested experimentally in the then-foreseeable future. That’s not science. A quarter century later and the theoretical physics community has yet to wake up and realize that there is new physics right under their noses – just not the new physics they’ve been expecting (GUTs, strings, membranes, etc.). Galaxy dynamics are consistent with a single, universal force law, but this unexpected behavior has largely been ignored because it doesn’t fit with particle theorists’ dreams of super symmetric dark matter particles. That we do not understand the observed behavior makes it more interesting than the “expected” (but unobserved) new physics: who ordered this?"

"The concordance model of cosmology, ΛCDM, provides a satisfactory description of the evolution of the universe and the growth of large scale structure. Despite considerable effort, this model does not at present provide a satisfactory description of small scale structure and the dynamics of bound objects like individual galaxies. In contrast, MOND provides a unique and predictively successful description of galaxy dynamics, but is mute on the subject of cosmology. … it is far from obvious that the mass spectrum of galaxy clusters or the power spectrum of galaxies can be explained in MOND, two things that ΛCDM does well. Critical outstanding issues are the development of an acceptable relativistic parent theory for MOND, and the reality of the non-baryonic dark matter of ΛCDM. Do suitable dark matter particles exist, or are they a modern aether?"

"People have been looking for this dark matter because there is a Nobel prize, for sure, waiting for whoever discovers it."

"I have experienced time and again people dismissing the data because they think MOND is wrong, so I am very consciously drawing a red line between the theory and the data."

"Why does MOND get any predictions right? It has had many a priori predictions come true. Why does this happen?"

"... I was deeply shocked when it was not my predictions or any of my immediate colleagues' predictions that came true in my data — but Milgrom's. This was completely outside my conceptual framework."

"A long time ago when I first got interested in MOND, having come from the background where I believed in dark matter, I wrote a proposal saying, "Gee, this theory had its predictions come true, ... we should look into that" and it was rejected, you know, very harshly. And I thought "OK, the community is not willing to fund this kind of thing" — this was almost twenty years ago. And so I basically did a global substitute, replaced MOND with dark matter, resubmitted, and I got my money. ... Pavel is totally correct that scientists are focused on getting grants, because that's what you need to support your students, and your postdocs, and getting the data, and all those sort of things. And I would like to believe that that was an anecdote from the distant past, but I am aware of a colleague who had this experience very recently where this person did not even mention MOND in the proposal, but the panel came back saying "MOND is no good — you must not spend money on this." ... the panel had associated ... this person's name with having at some point written a paper about MOND and projected that onto this proposal that ... did not mention MOND. And so it really is that bad."

"Whenever I come across a case that doesn't make sense in MOND, it usually doesn't make sense in either."

"... Dark matter provides the additional gravitational pull to bring model and reality broadly into alignment. Researchers now routinely take this model – Einstein plus dark matter, often called the ‘null hypothesis’ – as their starting point and then perform detailed calculations of galactic systems to test it. ... Most recently, Stacy McGaugh at Case Western Reserve University in Ohio and his team documented that the pattern of rotation in spiral galaxies seems to precisely follow the pattern of the visible matter alone, posing yet another challenge to the null hypothesis."

"The currently (2010) widely accepted/believed description of the birth and evolution of the universe and of its contents is "Lambda Cold Dark Matter Concordance Cosmological Model" (LCDM CCM) … My own research was very much confined to the early version of the LCDM CCM (mid-1990's) when I began performing numerical experiments on the satellite galaxies of the Milky Way. I was quite happy with the CCM, as everyone else, and did not bother with the fundamental issues raised by some. With time, however, it became apparent that the LCDM CCM accounts poorly for the properties of the satellite galaxies and their distribution about the Milky Way. Warm dark matter models fared no better."

"For me MOND is just as nonstandard as ΛCDM."

"MOND works far too well! In fact, just as planetary systems are Keplerian objects, galaxies are Milgromian objects. Milgrom’s discovery of a0 is likely as epochal as Planck’s discovery of h."

"The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist … The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations."

"The existence of dark matter particles can never be disproven by direct experiment because ever lighter particles and/or ever smaller cross sections just below the current detection threshold may be postulated for every non-detection. There exists no falsifiable prediction concerning the DM particles."

"Galaxies are observed to be simple systems following laws that result from scale-invariant dynamics which do not emanate from the haphazard merging history of halos of exotic dark matter."

"The existence of exotic dark matter particles outside the standard model of particle physics constitutes a central hypothesis of the current standard model of cosmology (SMoC). Using a wide range of observational data I outline why this hypothesis cannot be correct for the real Universe."

"The first step is that we need to revisit the validity of Newton’s universal law of gravitation. Starting in the 1980s, Mordehai Milgrom at the Weizmann Institute in Israel showed that a small generalisation of Newton’s laws can yield the observed dynamics of matter in galaxies and in galaxy clusters without dark matter. This approach is broadly known as MOND (MOdified Newtonian Dynamics). Milgrom’s correction allows gravitational attraction to fall off with distance more slowly than expected (rather than falling off with the square of distance as per Newton) when the local gravitational acceleration falls below an extremely low threshold. This threshold could be linked to other cosmological properties such as the ‘dark energy’ that accounts for the accelerating expansion of the Universe.These links suggest a deeper fundamental theory of space, time and matter, which has not yet been formulated."

"Community Reactions: "You are un-hireable" My (counter)Reaction: 1) "There is something not quite right with the community" 2) "Once one leaves the dark matter framework, real and correct predictions become possible""

"... MOND is the one theoretical description of gravitation which offers the greatest number of predictions which have been verified ..."

"The existence of of cosmological relevance has been ruled out with extreme (>5sigma) confidence using tests ..."

"Particulars are frequently fallible, but universals never. Occult philosophy lays bare Nature in her complete nakedness, and alone contemplates the wisdom of universals by the eyes of intelligence. Accustomed to partake of the rivers which flow from the Fountain of Life, it is unacquainted with grossness and with clouded waters."

"But absolutely nothing remains of that one and only medicament of which Hippocrates makes mention (darkly and mystically, I admit) in several places, and still less are its operations understood, inasmuch as no one now searches with lynx-like eyes into the profound depths of true natural philosophy, to gain an accurate knowledge of its composition and its virtues."

"Which of us has, at this day, the ability to discover those true and vivific numbers whereby the elements are united and bound to one another?"

"But, good God, what is this when compared with that deep and true music of the wise, whereby the proportions of natural things are investigated, the harmonical concord and the qualities of the whole world are revealed, by which also connected things are bound together, peace established between conflicting elements, and whereby each star is perpetually suspended in its appointed place by its weight and strength, and by the harmony of its lucent spirit"

"The art, also, of alchemy or chemistry is surrounded with such insoluble enigmas that we can scarcely gain anything but ignorance therefrom, and ignotum per ignotius."

"Geomancy was a natural art, drawing on the inborn powers of the human soul to glean information from the larger soul of the world."

"At the beginning of the 17th century many learned heads in England were occupied with Theosophy, Cabbalism, and Alchemy: amongst the proofs of this... may be cited the works of , of Norbert, of Thomas and Samuel Norton, but above all (in reference to our present inquiry) of Robert Fludd. Fludd it was, or whosoever was the author of the Summum Bonum 1629, that must be considered as the immediate father of Freemasonry, as Andrea was its remote father. What was the particular occasion of his own first acquaintance with , is not recorded: all the books of Alchemy or other occult knowledge, published in Germany, were at that time immediately carried over to England — provided they were written in Latin; and, if written in German, were soon translated for the benefit of English students. He may therefore have gained his knowledge immediately from the three Rosicrucian books. But it is more probable that he acquired his knowledge on this head from his friend Maier (mentioned in the preceding chapter) who was intimate with Fludd during his stay in England, and corresponded with him after he left it. At all events he must have been initiated into Rosicrucianism at an early period, having published his apology for it in the year 1617."

"THE central figure of Rosicrucian literature, towering as an intellectual giant above the crowd of souffleurs, theosophists, and charlatanic professors of the magnum opus, who, directly or otherwise, were connected with the mysterious Brotherhood, is Robertus de Fluctibus, the great English mystical philosopher of the seventeenth century, a man of immense erudition, of exalted mind, and, to judge by his writings, of extreme personal sanctity. Ennemoser describes him as one of the most distinguished disciples of Paracelsus, but refuses to number him with "those consecrated theosophists who draw all wisdom from the fountain of eternal light." He does not state his reasons for this depreciatory judgment, and the brief and inadequate notice which he gives of Fludd's system displays such a cursory acquaintance with the works in which it is developed, that it is doubtful whether he had taken pains to understand his author."

"Fludd's apology for the Brotherhood of the Rosy Cross was first issued in 1616, being printed in Leyden. It "entitles him to be regarded as the high priest of their mysteries." It is said that Maier visited Fludd in London in 1615, and the result of his visit was, we know, the publication of his 'Apologia,' written in Latin, and published in Leyden in 1616."

"MORAL REALITY AND MORAL FACTS -- https://www.whyarewehere.tv/people/george-ellis/"

"WHAT IS FINE-TUNING? -- https://www.whyarewehere.tv/people/george-ellis/"

"TOP-DOWN CAUSATION -- https://www.whyarewehere.tv/people/george-ellis/"

"THE ETERNAL TRUTHS OF MATHEMATICS -- https://www.whyarewehere.tv/people/george-ellis/"

""On the limits of quantum theory: Contextuality and the quantum–classical cut", Annals of Physics 327 (2012) 1890–1932"

"Above all he believes that these mathematically based speculations solve thousand year old philosophical conundrums, without seriously engaging those philosophical issues. The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy."

"You cannot do physics or cosmology without an assumed philosophical basis. You can choose not to think about that basis: it will still be there as an unexamined foundation of what you do."

"Attempts to explain values in terms of neuroscience or evolutionary theory in fact have nothing whatever to say about what is good or bad. That is a philosophical or religious question (scientists trying to explain ethics from these kinds of approaches always surreptitiously introduce some unexamined concept of what is a good life by the back door)."

"Actually philosophical speculations have led to a great deal of good science. Einstein’s musings on Mach’s principle played a key role in developing general relativity. Einstein’s debate with Bohr and the EPR paper have led to a great of deal of good physics testing the foundations of quantum physics. My own examination of the Copernican principle in cosmology has led to exploration of some great observational tests of spatial homogeneity that have turned an untested philosophical assumption into a testable – and indeed tested - scientific hypothesis. That’ s good science."

"Life, like science and art, is a theory about the world: a theory that in our case takes bodily form. By a succession of adaptations, most of which are favourable and none of which are lethal, living things have invested in particular expectations about the future course of their environments. If those theories are good enough, then life will prosper and multiply; but if they are outmoded by changing conditions, their embodiments will dwindle and perish."

"The laws of Nature are based upon the existence of a pattern, linking one state of affairs to another; and where there is pattern, there is symmetry. Yet...the symmetries that the laws enshrine are broken in... outcomes. Suppose that we balance a needle on its point and then release it. The law of gravity, which governs its subsequent motion, is perfectly democratic. It has no preference for any particular direction in the Universe: it is symmetrical in this respect. Yet, when the needle falls, it must fall in a particular direction. The directional symmetry of the underlying law is broken, therefore... By the same token, the fallen needle hides the symmetry of the law... Such 'symmetry-breaking' governs much of what we see in the Universe... It allows a Universe governed by a small number of symmetrical laws to manifest an infinite diversity of complex, asymmetrical states. This is how the Universe can be at once, simple and complicated."

"Hundreds of years ago, natural theologians tried to impress their readers with stories of the wondrous symmetries of Nature; now we see that, ironically, it is the departures from those symmetries that makes life possible. It is upon the flaws of Nature, not the laws of Nature, that the possibility of our existence hinges. ...The laws and constants of Nature are features that enforce uniformity and simplicity, while initial conditions and symmetry breakings permit complexity and diversity."

"Ancient belief in a cosmos composed of spheres, producing music as angels guided them through the heavens, was still flourishing in Elizabethan times. ...There is a good deal more to Pythagorean musical theory than celestial harmony. Besides the music of the celestial spheres (musica mundana), two other varieties of music were distinguished: the sound of instruments...(musica instrumentalis), and the continuous unheard music that emanated from the human body (musica humana), which arises from a resonance between the body and the soul. ...In the medieval world, the status of music is revealed by its position within the Quadrivium—the fourfold curriculum—alongside arithmetic, geometry, and astronomy. Medieval students... believed all forms of harmony to derive from a common source. Before Boethius' studies in the ninth century, the idea of musical harmony was not considered independently of wider matters of celestial or ethical harmony."

"If a 'religion' is defined to be a system of ideas that contains unprovable statements, then Gödel taught us that mathematics is not only a religion, it is the only religion that can prove itself to be one."

"A less inflexible picture of mathematics is one that focuses on the fact that it is an open-ended human activity. Inventionism is the belief that mathematics is nothing more than what mathematicians do. ...We invent mathematics; we do not discover it. ...The independent discovery of the same mathematical theorems by different mathematicians from totally different economic, cultural, and political backgrounds—often at widely separated times in history—argues against such a simple view. The inventionist could respond by pointing to the universality of human languages. ...One might expect that those aspects of this universal grammar that share features of logic, and hence counting, would also make counting appear instinctive. In fact, although simple counting... is fairly universal in ancient and primitive cultures, virtually none of them went on to carry out mathematical operations more sophisticated than counting. This suggests that these higher mathematical operations are not genetically programmed into the human brain... They are more likely to be by-products of multi-purpose pattern-recognition capabilities."

"Unfortunately, truth is neither a listable nor a decidable property; nor is the truth of a statement of arithmetic. The American logician John Myhill has used the term 'prospective' to characterize those attributes of the world that are neither listable nor decidable. They are properties that cannot be recognized by the application of some formula, made to conform to a rule, or generated by some computer program. They are characterized by incessant novelty that cannot be encompassed by any finite set of rules. 'Beauty', 'ugliness', 'truth', 'harmony', simplicity', and 'poetry' are names we give to some of the attributes of this sort. There is no way of listing all examples of beauty or ugliness, nor any procedure for saying whether or not something possesses either of those attributes, without redefining them in some more restrictive fashion that kills their prospective character."

"Our sensitivity to changes of pitch ... is underused in musical sound. Western music, in particular, is based on scales that use pitch changes that are at least twenty times bigger than the smallest changes that we could perceive. If we used our discriminatory power to full, we could generate an undulating sea of sound that displayed continuously changing frequency rather like the undersea sonic songs of dolphins and whales."

"Where there is life there is a pattern, and where there is a pattern there is mathematics. Once that germ of rationality and order exists to turn a chaos into a cosmos, then so does mathematics. There could not be a non-mathematical Universe containing living observers."

"Highly correlated brown and black noise patterns do not seem to have seem to have attractive counterparts in the visual arts. There, over-correlation is the order of the day, because it creates the same dramatic associations that we find in attractive natural scenery, or in the juxtaposition of symbols. Somehow, it is tediously predictable when cast in a one-dimensional medium, like sound."

"If musical appreciation is a by-product of a more general pattern-processing propensity of the brain, then why are our senses heightened by pink noises? It is significant that the world around us is full of variations with 1/f spectra. Benoit Mandelbrot has pioneered the study of natural and computer-generated patterns that are scale-free. (He calls them fractals...) Mandelbrot draws attention to the fact that there is a pattern to the noise spectrum displayed by the human nervous system. At the extremities of the body... it tends to be of white-noise form; but, as one approaches closer to the central nervous system and the brain, these variations become 1/f-like. Our nervous system may act as a spectral filter to prevent the brain from being swamped with uninteresting white background noise about the world..."

"The Universe has imposed aspects of its structure upon us by the inevitability of the forces of Nature... In a world where adapters succeed, but non-adapters fail, one expects to find vestigial remnants... Many of these adaptations... give rise to a suite of curious byproducts, some of which have played a role in determining our aesthetic sense. We are products of a past world where sensitivities to certain things were a matter of life or death."

"The various creation stories of ancient time were not scientific theories in any modern sense. They did not attempt to reveal anything new about the structures of the world; they aimed simply to remove the specter of the unknown from human imaginings."

"The secret of how galaxies came into being may well be fathomed by the study of the most elementary particles of matter in particle detectors buried deep underground; the identity of those elementary particles may be revealed by observations of distant starlight. ...by the coming together of the largest and the smallest aspects of the physical world our appreciation of the unity of the universe becomes more impressive and complete."

"What Hubble discovered was the expansion of the universe. ...We are not expanding. Nor is Brooklyn. Nor is earth. Nor is the solar system. Nor, in fact, is the Milky Way galaxy. Nor even those aggregates of thousands of galaxies that we call "galaxy clusters." These collections of matter are bound together by chemical and gravitational forces between their constituents—forces that are stronger than the force of expansion."

"Assuming the simulators, or at least the early generations of them, have a very advanced knowledge of the laws of Nature, it's likely that they would still have incomplete knowledge of them. ...gradually the little flaws will begin to build up. ...The only escape is if their creatures intervene to patch up the problems one by one as they arise."

"...logical contradictions will inevitably arise and the laws of the simulations will appear to break down now and again. The inhabitants of the simulation—especially the simulated scientists—will occasionally be puzzled by the experimental results they obtain. The simulated astronomers, might, for instance, make observations that show that their so-called constants of Nature are very slowly changing."

"Gods reappear in unlimited numbers in the guise of the simulators who have the power of life and death over the simulated realities that they bring into being. The simulators determine the laws, and can change the laws, that govern their worlds. They can engineer anthropic fine-tunings. They can pull the plug on the simulation at any moment, intervene or distance themselves from their simulation; watch as the simulated creatures argue about whether there is a god who controls or intervenes, work miracles or impose their ethical principles upon the simulated reality."

"Scanning the past millennia of human achievement reveals just how much has been achieved during the last three hundred years since Newton set in motion the effective mathematization of Nature. We found that the world is curiously adapted to a simple mathematical description. It is enigma enough that the world is described by mathematics; but by simple mathematics, of the sort that a few years energetic study now produces familiarity with, this is an enigma within an enigma."

"Ultimate explanation no longer means only a story that encompasses everything."

"By interlinking causes, by searching always for unity in the face of superficial diversity, modern scientific explanations prize depth above breadth. A deep and narrow theory can, and often does, graduate to become a deep and broad one. A broad and shallow theory never does."

"The legacy of the great monotheistic religions is the expectation of a single over-arching explanation for the Universe. ...There is no logical reason why the Universe should not contain surds of arbitrary elements that do not relate to the rest."

"We say that the string is 'random' if there is no other representation of the string which is shorter than itself. But we will say that it is 'non-random' if there does exist such an abbreviated representation. ...In general, the shorter the possible representation... the less random... On this view we recognize science to be the search for algorithmic compressions."

"It is simplest to think of mathematics as the catalogue of all possible patterns. ...When viewed in this way, it is inevitable that the world is described by mathematics. ...In many ways the search for a Theory of Everything is a manifestation of a faith that this compression goes all the way down to the bedrock of reality..."

"It is not hard to see why the Eastern holistic perspective made scientific progress so difficult. It denies the intuition that one can study the parts of the world in isolation from the rest—that one can analyze the world..."

"The living world is not a marble palace. It is a higgledy-piggledy outcome of natural selection and the competition between many interacting factors. The outcome is often neither elegant nor symmetrical."

"Each of the most basic physical laws that we know corresponds to some invariance, which in turn is equivalent to a collection of changes which form a symmetry group. ...whilst leaving some underlying theme unchanged. ...for example, the conservation of energy is equivalent to the invariance of the laws of motion with respect to translations backwards or forwards in time... the conservation of linear momentum is equivalent to the invariance of the laws of motion with respect to the position of your laboratory in space, and the conservation of angular momentum to an invariance with respect to directional orientation... discovery of conservation laws indicated that Nature possessed built-in sustaining principles which prevented the world from just ceasing to be. There were fewer roles for the Deity to play..."

"Even today, there persists... a feeling that the creation of the Universe out of nothing must violate some basic conservation law that stops one from getting something for nothing. Nevertheless, there is actually no evidence that the Universe as a whole possesses a non-zero value of any such conserved quantity. The total mass-energy of all the constituents of a finite Universe appears to be always equal in magnitude but opposite in sign to the total gravitational potential energies of those particles. ...Similarly, there is no evidence that the Universe possesses any overall net rotation or electric charge."

"There is no formula that can deliver all truth, all harmony, all simplicity. No Theory of Everything can ever provide total insight. For, to see through everything, would leave us seeing nothing at all."

"We have witnessed a revolution in the history of science. Not the sort of revolution that philosophers of science once believed in—they don't happen any more—but a revolution brought about by new tools, different ways of seeing, and novel ways of understanding. Nothing old needed to be overthrown to make way for the new. The future of science will be increasingly dominated by artificial images and simulations."

"Images and pictures... have played a key role in shaping our scientific picture of the world. ...Carefully constructed families of pictures can act as a calculus all their own. Like any successful systems of symbols, with an appropriate grammar they enlarge the number of things that we can do without consciously thinking."

"The advent of small, inexpensive computers with superb graphics has changed the way many sciences are practiced, and the way that all sciences present the results of experiments and calculations."

"Mathematics became an experimental subject. Individuals could follow previously intractable problems by simply watching what happened when they were programmed into a personal computer. ...The PC revolution has made science more visual and more immediate. ...by creating films of imaginary experiences of mathematical worlds. ...Words are no longer enough."

"Scientific pictures are often not just about science. They may... have an undeniable aesthetic quality. They may even have been primarily works of art that possess a scientific message."

"The abstractions of Einstein's curved space and time gave rise to analogies and pictures that played a new explanatory role. Space and time gave way to space-time, visible light was augmented by images across the rest of the electromagnetic spectrum, and we realised that we could see back towards the apparent beginnings of time."

"Copernicus' picture did more than picture the solar system correctly: it painted a new world picture."

"In the spring of 1845, William Parsons, the third Earl of Rosse, began observing with his great six-foot telescope... The Earl was excited by what he was the first human to see: spiral patterns of stars, seemingly swirling in great 'spiral convolutions' about the centre of the galaxy. ...No one could ever have seen the spiral pattern of stars in a galaxy unless they had looked through Rosse's telescope or seen his drawings. ...I believe that Van Gogh would have seen those drawings in the press following the publicity attracted by them, or in Flammarion's book... and gained his astronomical inspiration from them."

"If one looks at the special problems that were the mainsprings of progress along the oldest and most persistent lines of human inquiry, then one finds Nothing, suitably disguised as something, never far from the centre of things."

"The spooky ether was persistent. It took an Einstein to remove it from the Universe. ...Gradually, over the last twenty years, the vacuum has turned out to be more unusual, more fluid, less empty, and less intangible than even Einstein could have imagined. Its presence is felt on the very smallest and largest dimensions over which the forces of Nature act."

"There is a good deal more to nothing than meets the eye."

"Everyone knows there are billions and billions of stars, and national debts conjure up similar astronomical numbers. Yet we have found a way to hide the zeros: 109 doesn't look as bad as 1,000,000,000."

"The physicist's concept of nothing—the vacuum... began as empty space—the void... turned into a stagnant ether through which all the motions of the Universe swam, vanished in Einstein's hands, then re-emerged in the twentieth-century quantum picture of how Nature works."

"The logic of the Greeks prevents them having the idea at all and it is to the Indian cultures that we must look to find thinkers who are comfortable with the idea that Nothing might be something."

"The quantum revolution showed us why the old picture of a vacuum as an empty box was untenable. ...Gradually, this exotic new picture of quantum nothingness succumbed to experimental exploration... in the form of vacuum tubes, light bulbs and X-rays. Now the 'empty' space itself started to be probed. ...There was always something left: a vacuum energy that permeated every fibre of the Universe."

"Einstein showed us that the Universe might contain a mysterious form of vacuum energy. ...Last year, two teams of astronomers used Earth's most powerful telescopes... to gather persuasive evidence for the reality of the cosmic vacuum energy. Its effects are dramatic. It is accelerating the expansion of the Universe."

"The Indian religious traditions... accepted the concept of non-being on an equal footing with that of being. Like many other Eastern religions, the Indian culture regarded Nothing as a state from which one might have come and to which one might return.. Where Western religious traditions sought to flee from nothingness... a state of non-being was something to be actively sought by Buddhist and Hindus in order to achieve Nirvana: oneness with the Cosmos."

"The Greek tradition was a complete contrast to that of the Far East. ...the Greeks placed logic at the pinnacle of human thinking. Their sceptical attitude towards the wielding of 'non-being' as some sort of 'something' that could be subject to logical development was exemplified by Parmenides' influential arguments against the concept of empty space. ...He maintained that you can only speak about what is: what is not cannot be thought of, and what cannot be thought of cannot be. ...more unexpected was the further conclusion that time, motion nor change could exist either."

"The Indian system of counting is probably the most successful intellectual innovation ever devised by human beings. It has been universally adopted. ...It is the nearest thing we have to a universal language."

"Einstein showed us how to find all the possible universes that were consistent with the laws of physics and the character of gravity, how to reconstruct their pasts and predict their futures. But actually finding them was no easy task."

"Einstein had spent the previous thirty years showing how we could understand the behaviour of whole universes with simple maths. Gamow saw that those universes must have had a past that was unimaginably different to the present. What had stopped them both in their tracks was Gamow's suggestion that the laws of physics could describe something being created out of nothing."

"Just focusing on what exists now seems a bit exclusive. And if we include everything that has ever existed as part of the universe, why not include the future as well? This seems to leave us with the definition that the universe is everything that has ever existed, does exist, or will ever exist."

"Aristotle believed that the world did not come into being at some time in the past; it had always existed and it would always exist, unchanged in essence for ever. He placed a high premium on symmetry and believed that the sphere was the most perfect of all shapes. Hence the universe must be spherical. ...An important feature of the spherical shape... was the fact that when a sphere rotates it does not cut into empty space where there is no matter and it leaves no empty space behind. ...A vacuum was impossible. It could no more exist than an infinite physical quantity. ...Circular motion was the most perfect and natural movement of all."

"While we have no reason to expect that our position in the universe is special in every way, we would be equally misled were we to assume that it could not be special in any way."

"Location is not, as the estate agents say, everything. We must also consider our place in history."

"Continual miniaturisation allows resources to be conserved, efficiency to be increased, pollution to be reduced, and the remarkable flexibilities of the quantum world to be tapped. Very advanced civilizations elsewhere in the universe may have been forced to follow the same technological path. Their nano-scale space probes, their atomic-scale machines and nano-computers, would be imperceptible to our coarse-grained surveys of the universe. ...This may be the low-impact evolutionary path you need to follow in order to survive into the far, far future."

"In Theories of Everything... John Barrow argued that Gödel's incompleteness theorem undermines the very notion of a complete theory of nature. Gödel established that any moderately complex system of axioms inevitably raises questions that cannot be answered about the axioms. The implication is that any theory will always have loose ends. Barrow also pointed out that a unified theory of particle physics would not really be a theory of everything, but only a theory of all particles and forces. The theory would have little or nothing to say about phenomena that make our lives meaningful, such as love or beauty."

"[Time is not] a mysterious illusion of the intellect. ..It is an essential feature of the universe."

"Perhaps the first to approach the fourth dimension from the side of physics, was the Frenchman, Nicole Oresme, of the fourteenth century. In a manuscript treatise, he sought a graphic representation of the Aristotelian forms, such as heat, velocity, sweetness, by laying down a line as a basis designated longitudo, and taking one of the forms to be represented by lines (straight or circular) perpendicular to this either as a latitudo or an altitudo. The form was thus represented graphically by a surface. Oresme extended this process by taking a surface as the basis which, together with the latitudo, formed a solid. Proceeding still further, he took a solid as a basis and upon each point of this solid he entered the increment. He saw that this process demanded a fourth dimension which he rejected; he overcame the difficulty by dividing the solid into numberless planes and treating each plane in the same manner as the plane above, thereby obtaining an infinite number of solids which reached over each other. He uses the phrase "fourth dimension" (4am dimensionem)."

"Although the peculiarly fundamental nature of time in relation to ourselves is evident as soon as we reflect that our judgments concerning time and events in time appear themselves to be 'in' time, whereas our judgments concerning space do not appear themselves in any obvious sense to be in space, physicists have been influenced far more profoundly by the fact that space seems to be presented to us all of a piece, whereas time comes to us only bit by bit. The past must be recalled by the dubious aid of memory, the future is hidden from us, and only the present is directly experienced. This striking dissimilarity between space and time has nowhere had a greater influence than in physical science based on the concept of measurement. Free mobility in space leads to the idea of the transportable unit length and the rigid measuring rod. The absence of free mobility in time makes it much more difficult for us to be sure that a process takes the same time whenever it is repeated."

"Our conscious appreciation of the fact that one event follows another is of a different kind from our awareness of either event separately. If two events are to be represented as occurring in succession, then—paradoxically—they must also be thought of simultaneously."

"Whether the stars were all at the same distance, or whether they were scattered throughout infinite space, or whether they formed a finite system of vast but limited depth, were questions that could not be answered until towards the end of the eighteenth century. Until then, stellar astronomy was a field left to the unaided imagination."

"Although the classic theoretical foundation of distance measurement in physics is the 'rigid rod', nearly all distances in surveying, whether terrestrial or celestial, are made to depend on the properties of light. The two simplest properties so employed are the principle of propogation in straight lines and the principle that the intensity of light diminishes inversely as the square of the distance."

"Galileo had raised the concepts of space and time to the status of fundamental categories by directing attention to the mathematical description of motion. The midiaevel qualitative method had made these concepts relatively unimportant, but in the new mathematical philosophy the external world became a world of bodies moving in space and time. In the Timaeus Plato had expounded a theory that outside the universe, which he regarded as bounded and spherical, there was an infinite empty space. The ideas of Plato were much discussed in the middle of the seventeenth century by the Cambridge Platonists, and Newton's views were greatly influenced thereby. He regarded space as the 'sensorium of God' and hence endowed it with objective existence, although he confessed that it could not be observed. Similarly, he believed that time had an objective existence independent of the particular processes which can be used for measuring it."

"Let us suppose that an explosion occurs on Mars, which is observed by an astronomer on earth, who records the instant when he sees the flash. If light travelled instantaneously with an infinite velocity, this instant would coincide with the time... recorded by the... observer on Mars. In this way a meaning could be attached automatically to absolute time and the simultaneity of events at different places; indeed, the classical theory is now regarded as the limiting form of Einstein's theory when the velocity of light becomes infinite. But as there is a mass of experimental evidence supporting the view that light takes a finite time to travel... the terrestrial observer must correct the time recorded on his watch. This correction... will depend on assumptions concerning the velocity of light and the measurement of distance. Thus the concept of a world-wide simultaneity ceases to be a primitive idea."

"Consider an event, for example the outburst if a nova... Suppose this event is observed from two stars in line with the nova, and suppose further that the two stars are moving uniformly with respect to each other in this line. Let the epoch at which these stars passed by each other be taken as the zero of time measurement, and let an observer A on one of the stars estimate the distance and epoch of the nova outburst to be x units of length and t units of time, respectively. Suppose the other star is moving toward the nova with velocity v relative to A. Let an observer B on the star estimate the distance and epoch of the nova outburst to be x units of length and t units of time, respectively. Then the Lorentz formulae, relating x to t, arex' = \frac {x-vt}{\sqrt{1-\frac{v^2}{c^2}}} ; \qquad t' = \frac {t-\frac{vx}{c^2}}{\sqrt{1-\frac{v^2}{c^2}}} These formulae are... quite general, applying to any event in line with two uniformly moving observers. If we let c become infinite then the ratio of v to c tends to zero and the formulae becomex' = x - vt ; \qquad t' = t."

"Minkowski made a remarkable discovery concerning the Lorentz formulae. He showed that, although each observer has his own private space and private time, a public concept which is the same for all observers can be formed by combining space and time as a kind of 'distance' by multiplying it by the velocity of light, c; in other words, with any time interval we can associate a definite spatial interval, namely the distance which light can travel in empty space in that period. If, according to a particular observer, the difference in time between any two events is T, this associated spatial interval is cT. Then, if R is the space-distance between these two events, Minkowski showed that the difference of the squares of cT and R has the same value for all observers in uniform relative motion. The square root of this quantity is called the space-time interval between two events. Hence, although time and three-dimensional space depend on the observer, this new concept of space-time is the same for all observers."

"In developing his theory of gravitation, Newton assigned to every material body another property which is called its gravitational mass. Gravitational mass determines the force exerted by the body on other bodies, and so its function appears to be quite distinct from that of inertial mass. Nevertheless, the two are found to be identical in magnitude. Newton made experiments to verify this remarkable equality by swinging a pendulum with a bob which could be made with different materials. The period of the swing depended on the ratio of the inertial and gravitational masses of the pendulum, but in all cases it was found to be the same... In 1890 Eötvös made a much more refined test with the aid of a... torsion balance. Repeated experiments showed that inertial mass and gravitational mass were equal to within one part in 100 million. Einstein suggested that this was because inertia and gravitation are identical."

"According to the Special Theory of Relativity, the velocity of a moving body is always less than the velocity of light. Since the energy of motion of a body depends on its inertial mass and its velocity, it follows that if the energy of a body is increased indefinitely by the continual application of a force, the inertial mass of the body must be increased too; for, if not, the velocity would ultimately increase indefinitely and exceed the velocity of light. Einstein found that, corresponding to any increase in the energy content of a body, there is an equivalent increase in its inertial mass. Mass and energy thus appeared to be different names for the same thing, the energy associated with a mass M being Mc2, where c is the velocity of light; and the mass M of a body moving with velocity v he found to be given by the following formulaM = \frac {m}{\sqrt{(1 - \frac {v^2}{c^2}}}"

"Although the Special Theory of Relativity does not account for electromagnetic phenomena, it explains many of their properties. General Relativity, however, tells us nothing about electromagnetism. In Einstein's space-time continuum gravitational forces are absorbed in the geometry, but the electromagnetic forces are quite unaffected. Various attempts have been made to generate the geometry of space-time so as to produce a unified field theory incorporating both gravitational and electromagnetic forces."

"The philosophical consequences of the General Theory of Relativity are perhaps more striking than the experimental tests. As Bishop Barnes has reminded us, "The astonishing thing about Einstein's equations is that they appear to have come out of nothing." We have assumed that the laws of nature must be capable of expression in a form which is invariant for all possible transformations of the space-time co-ordinates and also that the geometry of space-time is Riemannian. From this exiguous basis, formulae of gravitation more accurate than those of Newton have been derived. As Barnes points out..."

"Space-time is curved in the neighborhood of material masses, but it is not clear whether the presence of matter causes the curvature of space-time or whether this curvature is itself responsible for the existence of matter."

"Another interesting feature of the Einstein universe is that in principle it could be circumnavigated by a ray of light... it is unlikely that the rays would converge with sufficient accuracy. Nevertheless it is interesting to consider the possibility that some of the stars and nebulae which we see may after all be only optical ghosts."

"The models of Einstein and de Sitter are static solutions of Einstein's modified gravitational equations for a world-wide homogeneous system. They both involve a positive cosmological constant λ, determining the curvature of space. If this constant is zero, we obtain a third model in classical infinite Euclidean space. This model is empty, the space-time being that of Special Relativity. It has been shown that these are the only possible static world models based on Einstein's theory. In 1922, Friedmann... broke new ground by investigating non-static solutions to Einstein's field equations, in which the radius of curvature of space varies with time. This Possibility had already been envisaged, in a general sense, by Clifford in the eighties."

"By the time of Comte, scientists unanimously rejected the idea that there was any essential difference between celestial and terrestrial matter, but they still had no empirical evidence to support their view any more than had Aristotle to support his, and to the positivist philosopher it seemed that none could ever be obtained. ...The possibility of a solution to this problem appeared shortly after Comte's pronouncement with the rise of the science of astronomical spectroscopy..."

"From a careful determination of the amount of solar heat that which would fall per minute on an area of one square centimetre placed perpendicular to the radiation as it falls on Earth's surface and from a knowledge of the Earth's distance, we deduce that each square centimetre of the solar surface radiates on the average of about the rate of a nine horse-power engine."

"The solution... was found only after the rise of nuclear physics, and, strange to relate, was not known to Eddington when he developed his celebrated theory of stellar structure between 1916 and 1924. Indeed, it is one of the most intriguing facts in the history of science that the two most influential theories concerning the stars—Newton's theory of gravitation and Eddington's theory of stellar construction—were each developed so successfully although Newton was ignorant of the origin of gravitation and Eddington of the origin of stellar energy."

"Not until the pioneer work of Rutherford and his colleagues was the possibility of nuclear reactions and transformations as sources of stellar energy envisaged."

"Newton's laws of motion and gravitation achieved their original success when applied to the solar system. The first definite evidence that they were applicable on a larger scale came from the study of binary stars towards the eighteenth century. In recent times the limitations of Newton's theory have become apparent. Even on the scale of the solar system, it has been challenged by Einstein's."

"As the degree of observational accuracy at which general relativity becomes significantly different from Newtonian theory is far from being achieved in this field, and as stellar velocities are small compared with light, there is no sign yet that any non-Newtonian theory is required."

"Cosmology is peculiar among the sciences for it is both the oldest and the youngest. From the dawn of civilization man has speculated about the nature of the starry heavens and the origin of the world, but only in the present century has physical cosmology split away from general philosophy to become an independent discipline."

"Einstein's pioneer application in 1917 of his newly developed general relativity to the problem of world-structure ushered in a new phase in the theoretical approach to the subject. Then, some seven years later, Hubble's discovery of Cepheid variables in the Andromeda nebula finally settled the long-debated question concerning this and similar nebulae in the Milky Way."

"It became clear that our Galaxy is only one system among many, and that the universe is far vaster than the particular stellar system to which the Sun and planets belong. Since then developments have been more rapid than at any time since the days of Copernicus, Digges and Bruno when the geocentric hypothesis of the cosmos received its death-blow."

"Man must have been conscious of memories and purposes long before he made any explicit distinction between past, present, and future."

"The famous palaeolithic paintings found in caves such as that at Lascaux in the Dordogne have been interpreted as evidence that, at least implicitly people were operating 20,000 or more years ago with teleological intent in terms of past, present, and future. It may well be that those responsible for the so-called 'Dancing Sorcerer' ...may have felt that the actual performance of the dance was insufficient, since they were concerned with the magical efficacy of the dance after it ended."

"It must have required enormous effort for man to overcome his natural tendency to live like the animals in a continual present."

"The development of rational thought actually seems to have impeded man's appreciation for the significance of time. ...Belief that the ultimate reality is timeless is deeply rooted in human thinking, and the origin of rational investigation of the world was the search for permanent factors that lie behind the ever-changing pattern of events."

"Language itself inevitably introduced an element of permanence into the world. For, although speech itself is transitory, the conventionalized sound symbols of language transcended time."

"To obtain a greater degree of permanence the time symbols of oral speech had to be converted into the space symbols of written speech. ...The crucial stage in the evolution of writing occurred when ideographs became phonograms..."

"Our idea of the universe as a whole remains a product of the imagination."

"The history of natural philosophy is characterized by the interplay of two rival philosophies of time — one aiming at its "elimination" and the other based on the belief that it is fundamental and irreducible."

"The basic objection to attempts to deduce the unidirectional nature of time from concepts such as entropy is that they are attempts to reduce a more fundamental concept to a less fundamental one."

"Most of the illustrations in this book were scanned... from the volumes in which they originally appeared. One of these deserves special mention. It is... from the library of the late Gerald James Whitrow... I was honoured to receive this small book as a gift in 2001 from Professor Whitrow's widow, Magda... I wished to include a copy of this historic image in my own book both as a tribute to Pofessor Whitrow's memory and to express my sincere gratitude to all responsible for the gift."

"Whitrow... proposed an anthropic resolution of the venerable philosophical question Why physical space has three dimensions? (arguing that with a space of different dimensionality there would be no living being to pose the question) and, similarly to [Grigory Moiseevich] Idlis, alluded around 1955 to an anthropic explanation of the size of the observable universe. Anyway, he never published these last ideas, which were developed years later by Wheeler. The only reference to Whitrow’s argument that appeared in print during the 1950s seems to be that due to the philosopher of religion Eric Lionel Mascall, who attributed to the English’s mathematician thatit may be necessary for the universe to have the enormous size and complexity which modern astronomy has revealed, in order for the earth to be a possible habitation for living beings."

"The point at issue between the two theories [A and B theory] is whether 'time' really is, in some deep ontological sense, differentiated into past, present and future. ...Reichenbach and Whitrow propose that there is indeed such a type of event and this is the 'becoming', or 'coming into being' of factual states-of-affairs in the physical world. ...Whitrow expressed ..."The past is the determined, the present is the moment of 'becoming' when events become determined, and the future is as-yet undetermined. Although neither Reichenbach nor Whitrow developed their thesis at any length, the general purport of what they meant is clear: there is a basic chance element in nature, at least at the micro-level, and the moment of 'becoming', which they identify with 'the present', is marked by a tranisition from what is merely possible to what is factual. However... this important attempt to provide a physical basis for the A-theory is by no means immune from criticism."

"While at Oxford, he was much influenced by cosmologist, E. A. Milne. ...Whitrow is... remembered for his very loud voice which could be heard 'from miles away.'"

"Remarks on the concept of simultaneity may mislead the reader to believing that only modern physicists and philosophers recognize the crucial importance of this notion. ...this concept has occupied the attention of philosophers and scientists throughout the whole history of human thought and played an important role in the writings of such intellectual giants as Aristotle, St. Augustine, Leibniz, and Kant. It would be a serious mistake to associate the concept of simultaneity exclusively with philosophic or scientific reasoning. In fact it was at the level of prescientific apprehension, a fundamental ingredient in the process of human apperception and conception of time. As Gerald Whitrow rightly pointed out, "our conscious appreciation of the fact that one event follows another is of a different kind from our awareness of either event separately. If two events are to be represented as occurring in succession, then—paradoxically—they must also be thought of simultaneously.""

"One of the few authors to have explicitly connected the physical issue of the expansion of the universe with the philosophical topic of the metaphysical status of space is Gerald James Whitrow."

"Whitrow's stance... is probably the first attempt to introduce such a philosophical approach in modern cosmology... it could be the a stimulus for new insights and a better comprehension of the physical foundations of cosmology itself."

"By combining prodigious scholarship from the ancient Greeks to modern physicists, he argued persuasively in more than 100 academic papers and a string of books that an integrated, interdisciplinary understanding of time should be possible."

"Much of Dr. Whitrow's work is concerned with problems in cosmology and relativity. ...He has been editor of The Observatory Magazine and the Monthly Notices of the Royal Astronomical Society."

"Perhaps the most important of Whitrow's books was The Natural Philosophy of Time. He showed that time can be studied independently of its magnitude. ...Whitrow's historical work included a paper on Robert Hooke."

"The shift toward a linear time conception, a confutation against (instead of a development from) the age-old cyclic time conception, did not occur suddenly and lasted well into the nineteenth century. ...Attention had clearly drifted away from seeking an eternally valid order toward a focus on change; truth had now ceased to lie in an unchanging order of things—rather, it tended to be regarded as dependent on process. Gerald Whitrow has put the matter succinctly, that in the nineteenth century " interest was transferred from the 'thing completed' to the genetic process, that is, from 'being' to 'becoming.' ""

"Professor Gerald Whitrow, who has died aged 87, wrote The Natural Philosophy of Time (1960) a tour de force that examined the subject from every side—mathematical, cosmological, historical, biological and psychological. ...As an opening for his talks, he would sometimes recount one of his favourite stories on time. It concerned the Russian poet Samuel Marshak, on a visit to London before 1914. Marshak's English was not too good and when he asked a man in the street "Please, what is time?", he received the surprised response, "But that's a big question. Why ask me?""

"There is no direct observational evidence for the curvature [of space], the only directly observed data being the mean density and the expansion, which latter proves that the actual universe corresponds to the non-statical case. It is therefore clear that from the direct data of observation we can derive neither the sign nor that value of the curvature, and the question arises whether it is possible to represent the observed facts without introducing the curvature at all. Historically the term containing the 'cosmological constant λ' was introduced into the field equations in order to enable us to account theoretically for the existence of a finite mean density in a static universe. It now appears that in the dynamical case this end can be reached without the introduction of λ."

"It was early 1932, when Einstein and I both were at the California Institute of Technology in Pasedena, and we just decided to look for a simple relativistic model that agreed reasonably well with the known observational data, namely, the Hubble recession rate and the mean density of matter in the universe. So we took the space curvature to be zero and also the cosmological constant and the pressure term to be zero, and then it follows straightforwardly that the density is proportional to the square of the Hubble constant. It gives a value for the density that is high, but not impossibly high. That's about all there was to it. It was not an important paper, although Einstein apparently thought that it was. He was pleased to have a simple model with no cosmological constant. That's it."

"[Einstein's cosmological constant] is a name without any meaning. ...We have, in fact, not the slightest inkling of what it's real significance is. It is put in the equations in order to give the greatest possible degree of mathematical generality."

"Our own galaxy system is only one of a great many, and observations made from any of the others would show exactly the same thing: all systems are receding, not from any particular centre, but from each other: the whole system of galaxies is expanding."

"Gradually... during the second half of the nineteenth century, the uncomfortable feeling of dislike of the action at a distance, which had been so strong in Huygens and other contemporaries of Newton, but had subsided during the eighteenth century, began to emerge again, and gained strength rapidly. This was favoured by the purely mathematical transformation (which can be compared in a sense with that from the Ptolemaic to the Copernican system), replacing Newton's finite equations by the differential equations, the potential becoming the primary concept, instead of the force, which is only the gradient of the potential. These ideas, of course, arose first in the theory of electricity and magnetism or perhaps one should say in the brain of Faraday.<!--"

"In electromagnetism... the law of the inverse square had been supreme, but, as a consequence of the work of Faraday and Maxwell, it was superseded by the field. And the same change took place in the theory of gravitation. By and by the material particles, electrically charged bodies, and magnets which are the things that we actually observe come to be looked upon only as "singularities" in the field. So far this transformation from the force to the potential, from the action at a distance to the field, is only a purely mathematical operation."

"The inconsistency of first explaining matter by atoms and then explaining atoms by matter was only slowly realised, and it is only comparatively recently that we have come to see that there is nothing paradoxical in the fact that an atom or an electron, which are not matter, may have properties different from those of matter, and must be allowed to do things that a material particle could not do."

"How does it come about that we have been able to find satisfactory hypotheses to explain electricity and magnetism, light and heat, in short all other physical phenomena, but have been unsuccessful in the case of gravitation?"

"Gravitation is entirely independent of everything that influences other natural phenomena. It is not subject to absorption or refraction, no velocity of propagation has been observed. You can do whatever you please with a body, you can electrify or magnetise it, you can heat it, melt or evaporate it, decompose it chemically, its behaviour with respect to gravitation is not affected. Gravitation acts on all bodies in the same way, everywhere and always we find it in the same rigorous and simple form, which frustrates all our attempts to penetrate into its internal mechanism."

"Gravitation is not only similar to inertia in its generality, it is also measured by the same number... the mass. The inertial mass is what Newton calls the "quantity of matter": it is a measure for the resistance offered by a body to a force trying to alter its state of motion. It might be called the "passive mass." The gravitational mass, on the other hand, is a measure of the force exerted by the body in attracting other bodies. We might call it the "active" mass. The equality of active and passive, or gravitational and inertial, mass was in Newton's system a most remarkable accidental co-incidence, something like a miracle. Newton himself decidedly felt it as such, and made experiments to verify it, by swinging a pendulum with a hollow bob which could be filled with different materials. The force acting on the pendulum is proportional to its gravitational mass, the inertia to its inertial mass: the period of its swing thus depends on the ratio between these two masses. The fact that the period is always the same therefore proves that the gravitational and inertial masses are equal."

"Gradually, during the eighteenth century, physicists and philosophers had become so accustomed to Newton's law of gravitation, and to the equality of gravitational and inertial mass, that the miraculousness of it was forgotten and only an acute mind like Bessel's perceived the necessity of repeating those experiments. By the experiments of Bessel about 1830 and of Eötvös in 1909 the equality of gravitational and inertial mass has become one of the best ascertained empirical facts in physics."

"In Einstein's general theory of relativity the identity of these two coefficients, the gravitational and the inertial mass, is no longer a miracle, but a necessity, because gravitation and inertia are identical."

"There is another side to the theory of relativity. We have pointed out in the beginning how the development of science is in the direction to make it less subjective, to separate more and more in the observed facts that which belongs to the reality behind the phenomena, the absolute, from the subjective element, which is introduced by the observer, the relative. Einstein's theory is a great step in that direction. We can say that the theory of relativity is intended to remove entirely the relative and exhibit the pure absolute."

"The sequence of different positions of the same particle at different times forms a one-dimensional continuum in the four-dimensional space-time, which is called the world-line of the particle. All that physical experiments or observations can teach us refers to intersections of world-lines of different material particles, light-pulsations, etc., and how the course of the world-line is between these points of intersection is entirely irrelevant and outside the domain of physics. The system of intersecting world-lines can thus be twisted about at will, so long as no points of intersection are destroyed or created, and their order is not changed. It follows that the equations expressing the physical laws must be invariant for arbitrary transformations."

"All systems are receding, not from any particular centre, but from each other: the whole system of galactic systems is expanding."

"Let the universe have only two dimensions, and let it be the surface of an india rubber ball. It is only the surface that is the universe, not the ball itself. ...Let there be specks of dust fixed to the surface to represent the different galactic systems. If the ball is inflated, the universe expands, and these specks of dust will recede from each other, their mutual distances, measured along the surface, will increase in the same rate as the radius of the ball. An observer in any one of the specks will see all the others receding from himself, but it does not follow that he is the centre of the universe. The universe (which is the surface of the ball, not the ball itself) has no centre."

"These... are the two observational facts about our neighbourhood, which have to be accounted for by the theory: there is a finite density of matter, and there is expansion, i.e. the mutual distances are increasing, and therefore the density is decreasing."

"Since we only consider the universe on a very large scale, and make abstraction of all details and local irregularities, our universe must be homogeneous and isotropic. It follows... that the three-dimensional space of it must be what mathematicians call a space of constant curvature."

"To help us to understand three-dimensional spaces, two-dimensional analogies may be very useful... A two-dimensional space of zero curvature is a plane, say a sheet of paper. The two-dimensional space of positive curvature is a convex surface, such as the shell of an egg. It is bent away from the plane towards the same side in all directions. The curvature of the egg, however, is not constant: it is strongest at the small end. The surface of constant positive curvature is the sphere... The two-dimensional space of negative curvature is a surface that is convex in some directions and concave in others, such as the surface of a saddle or the middle part of an hour glass. Of these two-dimensional surfaces we can form a mental picture because we can view them from outside... But... a being... unable to leave the surface... could only decide of which kind his surface was by studying the properties of geometrical figures drawn on it. ...On the sheet of paper the sum of the three angles of a triangle is equal to two right angles, on the egg, or the sphere, it is larger, on the saddle it is smaller. ...The spaces of zero and negative curvature are infinite, that of positive curvature is finite. ...the inhabitant of the two-dimensional surface could determine its curvature if he were able to study very large triangles or very long straight lines. If the curvature were so minute that the sum of the angles of the largest triangle that he could measure would... differ... by an amount too small to be appreciable... then he would be unable to determine the curvature, unless he had some means of communicating with somebody living in the third dimension....our case with reference to three-dimensional space is exactly similar. ...we must study very large triangles and rays of light coming from very great distances. Thus the decision must necessarily depend on astronomical observations."

"The triangles that we can measure are not large enough... to detect the curvature. Fortunately, however, we are, in a way, able to communicate with the fourth dimension. The theory of relativity has given us an insight into the structure of the real universe: ...a four-dimensional structure. The study of the way in which the three space-dimensions are interwoven with the time-dimension affords a kind of outside point of view of the three-dimensional space... from this outside point of view we might be able to perceive the curvature of the three-dimensional world."

"Matter is actually distributed very unevenly... conglomerated into stars and galactic systems. The average density is the density that we should get if all... could be evaporated into atoms of hydrogen, or protons, and... distributed evenly over the whole of space. ...three or four protons in every cubic foot. ...a million million times less than that of the most perfect vacuum that we can produce... The universe thus consists mostly of emptiness... consider a universe without any matter at all, an empty universe, as a good approximation. But we may also take as our first approximation a universe containing... three or four protons per cubic foot. The local deviations from the average, caused by the conglomeration of matter into stars and stellar systems, are then disregarded in the grand scale model, and are only taken into account when we come to study details."

"In the beginning of 1917, two solutions of the field equations for a homogeneous isotropic universe had been found, which I... call the solutions "A" and "B." ...at that time only static solutions were looked for. It was thought that the universe must be a stable structure...In one of these solutions (B) the average density was zero, it was empty; the other one (A) had a finite density. ...In B, to get the real universe, we should have to put in a few galactic systems, in A we should have to condense the evenly distributed matter into galactic systems. The universe A... has an average density, but no expansion. It is therefore called the static universe. B, on the other hand... expands, and it could only parade in the garb of a static universe because there is nothing in it to show the expansion. B is therefore called the empty universe. Thus we had two approximations : the static universe with matter and without expansion, and the empty one without matter and with expansion.The actual universe... has both matter and expansion... In 1917... the actual value of the density was still entirely unknown, and the expansion had not yet been discovered."

"In both the solutions A and B the curvature is positive, in both three-dimensional space is finite: the universe has a definite size, we can speak of its radius, and, in the case A, of its total mass. In the case A... the density is proportional to the curvature... Thus, if we wish to have a finite density in a static universe, we must have a finite positive curvature."

"The field equations, in their most general form, contain a term multiplied by a constant, which is denoted by the Greek letter &lambda;... sometimes called the "cosmical constant." This is a name without any meaning... We have, in fact, not the slightest inkling of what its real significance is. It is put in the equations in order to give them the greatest possible degree of mathematical generality, but, so far as its mathematical function is concerned, it is entirely undetermined: it may be positive or negative, it might also be zero."

"Purely mathematical symbols have no meaning by themselves; it is the privilege of pure mathematicians, to quote Bertrand Russell, not to know what they are talking about. ...It is the physicist, and not the mathematician, who must know what he is talking about."

"In February 1917, it was found that a static solution with a positive curvature—the solution A—was not possible without the &lambda;. In fact the curvature is proportional to &lambda; (in solution A, &lambda; is equal to the curvature; in B... it is three times the curvature). Thus, at the time when we had only the two static solutions A and B, and thought that these were the only possible ones, here was a plausible physical interpretation of the meaning of &lambda;: it was the curvature of the world, and the square root of its reciprocal, the radius of curvature, could be conceived as providing a natural unit of length."

"In the "static" universe expansion is impossible, the "empty" universe does expand. Therefore we may be tempted to consider the empty universe as the most likely approximation; and we can proceed to compute the radius of curvature of the universe, supposing it to be of the empty type, from the observed rate of expansion."

"Is the density anywhere near that corresponding to the static universe, or is it so small that we can consider the empty universe as a good approximation?"

"It is easy to compute the density of a static universe of a radius of two thousand million lightyears, and it comes out only very little larger than the observed density. The actual universe is thus very far from empty, it is, on the contrary, nearly full."

"We... come to the conclusion... that the actual universe is neither the static nor the empty one. It differs so much from both of these that neither can be used as an appropriate grand scale model. We must thus look for other solutions of the general field-equations. On account of the expansion our solution must necessarily be a non-static one, and it must have a finite density. There is only one possible static solution possessing a finite density, viz. our old friend A, but of non-static solutions with finite density there exists a great variety."

"We had become so accustomed to think of &lambda; as an essentially positive quantity, and of a finite world with positive curvature, that the idea of investigating the possibility of solutions with negative or zero values of &lambda; and of the curvature simply did not arise. But when this oversight was corrected, it appeared at once that in the non-static case both &lambda; and the curvature need not be positive, but can be negative or zero quite as well."

"The way in which the universe expands is determined by the variation of this [radius of curvature] R with the time. There are three types, or families, of non-static universes... the oscillating universes, and the expanding universes of the first and of the second kind. ...each of these is a representative of a family, comprising an infinite number of members differing in size and shape. ...In the expanding family of the first kind the radius is continually increasing from... zero... In the expanding series of the second type the radius has at the initial time a certain minimum value, different for the different members of the family. [Both kinds of expanding families] become infinite after an infinite time."

"Observations give us two data, viz. the rate of expansion and the average density, and there are three unknowns: the value of &lambda;, the sign of the curvature, and the scale of the figure, i.e. the units of R and of the time. The problem is indeterminate."

"If the curvature is small (as we know it must be, because it is imperceptible by ordinary geometric methods in our neighbourhood), then &lambda; must be small, and if the curvature is very small, then &lambda; must be very small. On the other hand, if &lambda; is very small, or zero, then the curvature must be very small, and may even be zero."

"It sounds rather strange to talk of an infinite universe still expanding. If we were certain that the curvature was negative, we might still, as in the case of positive curvature, replace the phrase "the universe expands" by the equivalent one "the curvature of the universe decreases." But if the curvature is zero, and remains zero throughout, what sort of meaning are we to attach to the "expansion"? The real meaning is, of course, that the mutual distances between the galactic systems, measured in so-called natural measure, increase proportionally to a certain quantity R appearing in the equations, and varying with the time. The interpretation of R as the "radius of curvature" of the universe, though still possible if the universe has a curvature, evidently does not go down to the fundamental meaning of it."

"The manner in which time and space are bound up with each other in the four-dimensional continuum is variable. It is difficult to express this variability of the cross-connections between space and time in simple language, and different interpretations of it are possible, corresponding to different mathematical transformations of the fundamental line-element, e.g. a different choice of the variable which we interpret as "time." Perhaps the best way we can express it is by saying that the solution of the field-equations of the theory of relativity shows that there is in the universe a tendency to change its scale, which at the present time results in an expansion, but may perhaps at other times become, or have been, a shrinking. This is true of the grand scale model of the universe."

"If we put in the details, the singularities of the field, viz. the galactic systems and the stars, we find that there is... a tendency, called gravitation, to decrease the mutual distances of these "singularities." At short distances, within the confines of a galactic system, this second tendency is by far the strongest, and the galactic systems retain their size independent of the expansion or contraction of the universe..."

"A question which has long troubled astronomers and physicists is what becomes of the energy that is continually being poured out into space by the sun and the stars. To this question a complete answer is given by the new theory. It is used up, diluted, or degraded, by the expansion of the universe. ...the light travelling through the expanding universe and, so to say, trying to reach a particular star, or stellar system, which is continually receding with great velocity, is losing energy in trying to catch up with it. It is this degradation of the light, technically known as the redshift of the spectral lines, by which we become aware of the receding velocities of the extra-galactic nebulae. It can be shown that the decrease of the total amount of radiant energy in the universe by this degradation exceeds the increase by the radiation of the stars. It would not be correct, however, to conclude that the expansion is caused by the energy thus lost by the radiation..."

"It is possible to relegate the epoch of the starting of the expansion to minus infinity, e.g. by using instead of the ordinary time the logarithm of the time elapsed since the beginning. But this is only a mathematical trick. We call zero minus infinity, but that only means that we allow the universe an infinite time to get well started on its course of expansion, but it does not make the time during which anything really happens any longer."

"The "universe" is an hypothesis, like the atom, and must be allowed the freedom to have properties and to do things which would be contradictory and impossible for a finite material structure. What we observe are the stars and nebulae constituting "our neighbourhood." All that goes beyond that, in time or in space, or both, is pure extrapolation.The conclusions derived about the expanding universe depend on the assumed homogeneity and isotropy, i.e. on the hypothesis that the observed finite material density and expansion of our neighbourhood are not local phenomena, but properties of the "universe." It is not inconceivable that this hypothesis may at some future stage of the development of science have to be given up, or modified, or at least differently interpreted."

"In astronomy two characteristics are common to all data on which the solution of the great problems depends. The first is the extreme minuteness of the quantities to be measured. ...New epochs were inaugurated in the beginning of the seventeenth century by the invention of the telescope, and in the last third of the nineteenth by the discovery of photography and spectroscopy....The other characteristic is that astronomy always requires a very large number of data. ...These two characteristics of the data that the astronomer requires to build his science on make two things more necessary in astronomy than in any other science: patience and organised coöperation. ...The astronomer—each working at his own task...—is always conscious of belonging to a community, whose members, separated in space and time, nevertheless feel joined by a very real tie, almost of kinship. ...whatever his special work may be it is always a link in a chain, which derives its value from the fact that there is another link to the left and one to the right of it. It is the chain that is important, not the separate links."

"Both the law of inertia and the law of gravitation contain a numerical factor or a constant belonging to matter, which is called mass. We have thus two definitions of mass; one by the law of inertia: mass is the ratio between force and acceleration. We may call the mass thus defined the inertial or passive mass, as it is a measure of the resistance offered by matter to a force acting on it. The second is defined by the law of gravitation, and might be called the gravitational or active mass, being a measure of the force exerted by one material body on another. The fact that these two constants or coefficients are the same is, in Newton's system, to be considered as a most remarkable accidental coincidence and was decidedly felt as such by Newton himself. He made experiments to determine the equality of the two masses by swinging a pendulum, of which the bob was hollow and could be filled up with different materials. The force acting on the pendulum is proportional to its active mass, its inertia is proportional to its passive mass, so that the period will depend on the ratio of the passive and the active mass. Consequently the fact that the period of all these different pendulums was the same, proves that this ratio is a constant, and can be made equal to unity by a suitable choice of units, i.e., the inertial and the gravitational mass are the same. These experiments have been repeated in the nineteenth century by Bessel, and in our own times by Eötvös and Zeeman, and the identity of the inertial and the gravitational mass is one of the best ascertained empirical facts in physics-perhaps the best. It follows that the so-called fictitious forces introduced by a motion of the body of reference, such as a rotation, are indistinguishable from real forces. ...In Einstein's general theory of relativity there is also no formal theoretical difference, as there was in Newton's system. ...the equality of inertial and gravitational mass is no longer an accidental coincidence, but a necessity."

"We know by actual observation only a comparatively small part of the whole universe. I will call this "our neighborhood." Even within the confines of this province our knowledge decreases very rapidly as we get away from our own particular position in space and time. It is only within the solar system that our empirical knowledge extends to the second order of small quantities (and that only for g44 and not for the other g&alpha;&beta;), the first order corresponding to about 10-8. How the g&alpha;&beta; outside our neighborhood are, we do not know, and how they are at infinity of space or time we shall never know. Infinity is not a physical but a mathematical concept, introduced to make our equations more symmetrical and elegant. From the physical point of view everything that is outside our neighborhood is pure extrapolation, and we are entirely free to make this extrapolation as we please to suit our philosophical or aesthetical predilections—or prejudices. It is true that some of these prejudices are so deeply rooted that we can hardly avoid believing them to be above any possible suspicion of doubt, but this belief is not founded on any physical basis. One of these convictions, on which extrapolation is naturally based, is that the particular part of the universe where we happen to be, is in no way exceptional or privileged; in other words, that the universe, when considered on a large enough scale, is isotropic and homogeneous."

"De Sitter's redshift phenomenon is not caused by the Doppler effect of stars moving away. It is a property of space-time, which appears when these are forced into the bitter conditions of the empty universe with the lambda-term. ...de Sitter was the first to suggest, in 1917 when galaxies were not yet known, that one should try to find a redshift-distance relation for very remote celestial bodies. ...Even Friedmann, who five years later demonstrated the possibility of an expanding universe, failed to point out the redshift phenomenon as a property of his own model."

"In 1916 and 1917 de Sitter presented to the Royal Astronomical Society a series of three papers on "Einstein's Theory of Gravitation and its Astronomical Consequences." Because there was no communication between Germany and England during World War I, these papers were instrumental in introducing general relativity to the English scientific community, and they played an important part in the decision of Arthur Eddington and others to send expeditions to observe the solar eclipse of 1919..."

"Hubble, who knew nothing of the work of Friedmann and Lamaître, had read de Sitter, whose sometimes comic absentmindedness masked a supple and inventive mind. Stimulated by one of Einstein's papers on general relativity penned in 1916, de Sitter entered into a fruitful correspondence with its author and soon produced three lengthy papers of his own on the subject. In the third article, published in 1917, he simplified his calculations by assuming that the universe is devoid of matter, a mathematical fiction that he defended on the basis that the real universe is composed mostly of space anyway. He then conjectured that if two stationary objects were introduced into this void, light passing between them with respect to one another would be redshifted. Curiously, the redshift is not due to either the expansion of intergalactic space or the Doppler effect. Instead, it is the effect of the mysterious slowing down of time at great distances. ...the amount of reshift in de Sitter's model was directly proportional to the distance between the emitting and receiving objects, a relationship that had only to be tested by someone with a telescope powerful enough..."

"If de Sitter's solution were valid everywhere, then it would be thereby shown that the purpose which I pursued with the introduction of the &lambda;-term has not been reached. In my opinion the general theory of relativity only forms a satisfactory system if according to it the physical qualities of space are completely determined by matter alone. Hence no g&mu;v-field must be possible, i.e., no space-time-continuum, without matter that generates it."

"From 1916 Einstein and de Sitter corresponded extensively on exactly what kind of universe best fit the relativity equations. De Sitter initially developed a model of a spherical universe, in contrast to the cylindrical one Einstein had envisioned. De Sitter also tried to map out the shape of the spherical universe in absence of all matter. Einstein's reaction to de Sitter's model was strong and negative...de Sitter's sphere described a universe that changed in size instead of remaining nicely constant. ... Einstein saw matter—and its corresponding gravitational field—as what inherently created the shape of the universe. He cited what he dubbed "Mach's principle,"...the movements of any object ...were determined by all other bodies in the universe. ...how a body moves through space is tantamount to what shape space is, the concept of "shape" without matter, Einstein insisted, was meaningless."

"In 1913, Willem de Sitter suggested that fast-moving binary stars... could be used to measure the effect of a moving source on the speed of light. Various experiments of this sort over the past eight decades have verified that the speed of light received from a moving star is the same as that from a stationary star... a wealth of other detailed experiments have been carried out during the past century..."

"De Sitter pointed out that some... pairs of stars have orbits aligned so that each star is either coming towards us or going away from us as it goes round its orbit. If the speed of light is modified by the motion of the star then 'faster' light from positions when the star is approaching the Earth could catch up with 'slower' light emitted earlier when the star was moving away from us in its orbit. There would then arise the possibility of multiple ghost images. Such ghost images have not been observed... de Sitter concluded that Einstein was right... it has been argued that one needs to be careful in accepting de Sitter's binary star argument... because of a phenomenon called 'extinction.' ...To avoid this problem, the binary experiment has... been repeated with stars emitting X-rays... experiment conclusively confirmed Einstein's postulate."

"The outstanding feature... is the possibility that the velocity-distance relation may represent the de Sitter effect, and hence that numerical data may be introduced into discussions of the general curvature of space. In the de Sitter cosmology, displacement of the spectra arises from two sources, an apparent slowing down of atomic vibrations and a general tendency of material particles to scatter. The latter involves an acceleration and hence introduces the element of time. The relative importance of these two effects should determine the form of the relation between distances and velocities; and in this connection it may be emphasized that the linear relation found in the present discussion is a first approximation representing a restricted range in distance."

"If anything, de Sitter disliked Milne's program even more than Eddington's. In this dislike, he was soon joined by Herbert Dingle. ...de Sitter came to good knowledge of the genuine, actual, empirical basis of astronomical science. Secondly, reducing the observational data from the Jovian satellites practiced the young astronomer's mathematical skills in thorough and useful ways. Such a powerful combination of two skills—empirical, observational skill plus theoretical, mathematical skill—was lacking in the colleagues with whom de Sitter would later practice cosmology—with the interesting exception of Dingle."

"In "Kosmos", de Sitter shows how steps forward in the development of science can be associated with scientists, who considered the Universe from a non-static, dynamic point of view. Charles Darwin is cited as one of the examples. ...From early on, de Sitter was actively engaged in the debate between Einstein, LeMaître, Eddington and others in the significance of the General Theory of Relativity for cosmology. De Sitter found in his preferred solutions of Einstein's field equations that the Universe was expanding and the relative velocity V of recession was expected to be in proportion to the distance r. De Sitter was searching for observational evidence of such a relative recession and turned to Kapteyn for advice on the feasibility..."

"In 1917 de Sitter showed that Einstein's field equations could be solved by a model that was completely empty apart from the cosmological constant—i.e. a model with no matter whatsoever, just dark energy. This was the first model of an expanding universe. although this was unclear at the time. The whole principle of general relativity was to write equations for physics that were valid for all observers, independently of the coordinates used. But this means that the same solution can be written in various different ways... Thus de Sitter viewed his solution as static, but with a tendency for the rate of ticking clocks to depend on position. This phenomenon was already familiar in the form of gravitational time dilation... so it is understandable that the de Sitter effect was viewed in the same way. It took a while before it was proved (by Weyl, in 1923) that the prediction was of a redshifting of spectral lines that increased linearly with distance (i.e. Hubble's law). ..."

"The theorists of the time were still debating whether the universe obeyed Einstein's static model, in which no red-shift is seen, or a model by Willem de Sitter in which the universe is expanding, and distant objects are red-shifted, but the universe contains no matter. ...Few astronomers were aware of the more general expanding universe solutions found by Georges Lemaître, and, especially, Alexander Friedmann, who had found in 1922-24 a complete set of solutions for Einstein's equations for the cosmological problem. Following Hubble's paper it was quickly realized that the expanding universe solutions were the ones that were needed to understand his observations."

"De Sitter made observations in 1913 of double-star systems and became the first astronomer to prove that the velocity of light had nothing to do with the velocity of its source. ...De Sitter ...published three papers entitled "On Einstein's Theory of Gravitation and Its Astronomical Consequences. The first two... explained Einstein's theories, and the third proposed his own interpretation of the astronomical consequences... de Sitter and Einstein published a joint paper in which they proposed there may be in the universe large amounts of matter that does not emit light and consequently has not been detected. This became known as "dark matter"..."

"Shortly after Einstein published his original memoir on cosmology in 1917, de Sitter constructed an alternative static world-model, which satisfied the same laws of world-gravitation. In this model, unlike Einstein's, space-time has an intrinsic structure of its own, independent of the presence of matter. ...there is ...no matter nor radiation. Nebulae... must therefore be considered as 'test particles,' having no influence on the model as a whole. ...whereas a test particle in Einstein's universe will remain at rest if it has no intitial motion, a similar particle... in de Sitter's world will immediately acquire an ever-increasing velocity of recession from the observer. ...in de Sitter's model space-time is 'hyperbolic'. There is no absolute time, and each observer will perceive a horizon at which time will appear to stand still... This phenomenon... is only apparent, like a rainbow. At any point on the (relative) horizon the time-flux experienced by an observer there will be the same as at the original observer. Thus in de Sitter's world there will be an apparent slowing-down of distant atomic vibrations, if these keep standard time. Consequently the radiation from a distant nebula will appear to be shifted toward the red, due to an increase in wave length corresponding to the decrease in vibrational frequency. This effect... will be supplemented by the Doppler effect, due to the relative recession of the nebula regarded as a test particle."

"It is clear that at best de Sitter's world, like Einstein's, can be regarded only as a limiting form of the real world. In the Einstein world there is the greatest possible concentration of matter without motion. In the de Sitter world there is motion but no matter. However, with... a special hypothesis due to Weyl... a nebula introduced into the de Sitter world will exhibit a red-shift proportional to its distance, similar to Hubble's observational law."

"In 1932, Einstein and de Sitter, in a joint memoir, argued that the original objections of 1917 to a world model of finite density in Euclidean space no longer applied if space could be regarded as expanding. ...Einstein and de Sitter therefore constructed a homogeneous world-model of finite density, subject to the field equations of General Relativity in expanding Euclidean space. They found... their model predicted a smoothed-out density of... 4 x 10-28 grammes per cubic centimetre. Although... "perhaps on the high side... we must conclude... it is possible to represent the facts without assuming a curvature of three-dimensional space.""

"He [de Sitter] reminds us that in Einstein's paper of November 1915 the &Lambda; term did not appear at all. Hence, &Lambda; had obviously the value zero. Cosmologically speaking, this implies that the curvature of the Universe is proportional to &Lambda;. In 1917, two solutions of Einstein's field equations for a homogeneous, isotropic universe were offered. ...in A the universe has a finite density, whereas in B, the average density is zero ...We are confronted with a static unverse containing matter and having no expansion on the one hand, and on the other an empty universe void of matter and expanding... when these two solutions were constructed, the expansion of the universe had not yet been discovered."

"De Sitter proposed three types of nonstatic universes: the oscillating universes and the expanding universes of the first or second kiind. The main characteristic of the expanding "family" of the first kiind is that the radius is continually increasing from a definite initial time when it had the value zero. The universe becomes infinitely large after an infinite time. In the second kind... the radius possesses at the initial time a definite minimum value... in the Einstein model... the cosmological constant is supposed to be equal to the reciprocal of R2, whereas de Sitter computed for his interpretation the constant to be equal to 3/R2. Whitrow correctly points out the significant fact that in special relativity the cosmological constant is omitted..."

"... the inflationary paradigm is so flexible that it is immune to experimental and observational tests. First, inflation is driven by a hypothetical , the inflaton, which has properties that can be adjusted to produce effectively any outcome. Second, inflation does not end with a universe with uniform properties, but almost inevitably leads to a multiverse with an infinite number of bubbles, in which the cosmic and physical properties vary from bubble to bubble. The part of the multiverse that we observe corresponds to a piece of just one such bubble. Scanning over over all possible bubbles in the multiverse, everything that can physically happen does happen an infinite number of times. No experiment can rule out a theory that allows for all possible outcomes. Hence, the paradigm of inflation is unfalsifiable."

"String theory suggested that we should have a whole new set of particles called "supersymmetric partners" that were supposed to be observed at the Large Hadron Collider at CERN — we don't see those."

"(quote at 33:07 of 49:06)"

"I know of no other scientist, no other theoretical physicist alive who has a clearer focus on whether our theories and ideas are relevant to the real world. And that's always what he's after."

"In the emerging picture of mankind in the universe, the future (if it exists) will surely entail discoveries about space and time which will open up whole new perspectives in the relationship between mankind, mind, and the uni-verse.… But what is now? There is no such thing in physics;it is not even clear that ‘now’ could ever be described, let alone explained, in terms of physics.… Notions such as ‘the past,’ ‘the present’ and ‘the future’ seem to be more linguistic than physical.… There is no universal now, but only a personal one—a ‘here and now.’ This strongly suggests that we look to the mind, rather than to the physical world, as the origin of the division of time into past, present, and future.…There is none of this in physics.… No physical experiment has ever been performed to detect the passage of time. As soon as the objective world of reality is considered, the passage of time disappears like a ghost into the night."

"Science, it is usually believed, helps us to build a picture of objective reality – the world 'out there'. With the advent of the quantum theory, that very reality appears to have crumbled, to be replaced by something so revolutionary and bizarre that its consequences have not yet been properly faced."

"All this prompts the question of why, from the infinite rage of possible values that Nature could have selected for the fundamental constants, and from the infinite variety of initial conditions that could have characterized the primeval universe, the actual values and conditions conspire to produce the particular range of special features that we observe. For clearly the universe is a very special place: exceedingly uniform on a large scale, yet not so precisely uniform that galaxies could not form; extremely low entropy per proton, and hence cool enough for chemistry to happen; almost zero cosmic propulsion and an expansion rate tuned to that energy content to unbelievable accuracy; values for the strengths of its forces that permit nuclei to exist, yet do not burn up all the cosmic hydrogen, and many more apparent accidents of fortune."

"The brain is the medium of expression of the human mind. Similarly the entire physical universe would be the medium of expression of the mind of a natural God."

"That the universe has organized its own self-awareness – is for me powerful evidence that there is 'something going on' behind it all. The impression of design is overwhelming. Science may explain all the processes whereby the universe evolves its own destiny, but that still leaves room for there to be a meaning behind existence."

"Matter as such has been demoted from its central role, to be replaced by concepts such as organization, complexity and information."

"The scientific quest is a journey into the unknown."

"What is remarkable is that human beings are actually able to carry out this code-breaking operation, that the human mind has the necessary intellectual equipment for us to "unlock the secrets of nature"..."

"Human beings have always been struck by the complex harmony and intricate organization of the physical world. The march of the heavenly bodies across the sky, the rhythms of the seasons, the pattern of a snowflake, the myriads of living creatures so well adapted to their environment – all these things seem too well arranged to be a mindless accident."

"I cannot believe that our existence in this universe is a mere quirk of fate, an accident of history, an incidental blip in the great cosmic drama. Our involvement is too intimate."

"In each and every one of us lies a message. It is inscribed in an ancient code, its beginnings lost in the mists of time. Decrypted, the message contains instructions on how to make a human being. Nobody wrote the message; nobody invented the code. They came into existence spontaneously. Their designer was Mother Nature herself, working only within the scope of her immutable laws and capitalizing on the vagaries of chance.The message isn't written in ink or type, but in atoms, strung together in an elaborately arranged sequence to form DNA, short for deoxyribonucleic acid. It is the most extraordinary molecule on Earth."

"The laws of nature are rigged not only in favor of complexity, or just in favor of life, but also in favor of mind. To put it dramatically, it implies that mind is written into the laws of nature in a fundamental way."

"To a physicist like me, life looks to be little short of magic: all those dumb molecules conspiring to achieve such clever things!"

"The thing that separates life from non-life is information."

"Seventy-five years ago Erwin Schrödinger published... '... the key point... was whether life can be explained by physics. ...Schrödinger ...said "We must be prepared to find a new kind of physical law prevailing...""

"[W]e... need some new physics. ...The attempt to square the circle by starting out with known physics at the atomic level and somehow life emerging at some higher level... I... don't think we're going to be able to do it without new physics."

"[[Max Delbrück|[M]ax Delbrück]]... expressed it... (to encapsulate)... [A]t the level of atoms it's just known physics, but at the level of the living cell it's some sort of magic."

"We lack any sort of device that can... detect life. We don't have a life meter. ...We don't have a general purpose life meter that can detect life as we don't know it."

"The fundamental problem about trying to define life... If you go to a physics department... you'll be given a definition in terms of matter... force... energy... entropy... free energy, molecular binding affinities, and so on. If you go to a biology department... you'll be given a very different narrative in terms of... instructions, transcription, , translation, coding, signals..."

"[B]iologists... define life in terms of its informational qualities... physicists tend to define life in terms of the physical qualities."

"[[Information theory|[I]nformation]] pervades biology. Your DNA is chock full of encrypted information, and the encryption is really important. But s don't act in isolation. They couple together to form networks, sometimes of great complexity, and information swirls around these networks. It can be stored.... processed... and it can have knock-on effects... beyond individual cells. Even bacteria can signal each other chemically... electrically and mechanically, and so, through physical forces, can exchange information and engage in cooperative behavior, like in s."

"[A]nts... have... collective decision-making... a labyrinth of [network] information exchange... which can profoundly affect the outcome of the colony. We see it... in bird flocking."

"Perhaps the most exquisite example of information in biology... During embryogenesis there's the most meticulous choreography of organized information, so all the right bits end up in the right place, at the right time. ...[T]he power of information to sculpt [living] physical forms."

"[T]hat great information processing system between our ears... probably ...the grandest example we know of... in the universe."

"This web of information extends beyond individual organisms and communities of organisms to a planetary scale. ...Andrew Kim and Harrison Smith... looked at over 28,000 genomes and... produced this... plot of information being organized on a... planetary scale. ...[T]he biosphere was the original ."

"Paul Nurse ...in his visionary essay ..."Life, Logic and Information" extols the virtues of thinking in an information, web-based way about life, and how, instead of worrying... about... the molecular level, we should think of life as being a collection of logic modules... with information flowing between them... control systems... [an] engineering approach."

"[W]ith the physics of living matter, have we joined... the world of physics with the world of informational biology?"

"[[Information theory|[I]nformation]]... has been in physics for a long time, in the most obvious way with Maxwell's demon... It was... just a Gedanken-Experiment... in 1867, but just in recent years, engineers (nanotechnologists) have built real Maxwell demons, and this is now something of a cottage industry."

"[[Maxwell's demon|[T]he demon]]... is transferring heat from a colder region to a warmer region in apparent defiance of the second law of thermodynamics. ...[A] refrigerator... costs energy to run... but the demon is operating using information instead... The demon... runs without any energy expenditure."

"So in effect, information serves as a fuel, and this leads to the whole concept of information engines. Engines that will run on information power..."

"Life was onto this... billions of years ago. Life uses many many nano-molecules... in effect, Maxwell demons. Our bodies are full of [them]... doing the business of life. ...not quite perfect ...but they're coming pretty close to the theoretical limit, in terms of energy expenditure."

"s are the way in which... you are thinking and paying attention, because the signals that travel between neurons, down the s, are controlled by the flow of s across the membranes of the axons... [T]hey are, in effect, little demons that sense the incoming signal and open and close the gates; and the ions flow. ...[T]his is so incredibly energy efficient that ...your brain, which is like a megawatt supercomputer, operates with the energy equivalent of a small light bulb."

"It's now commonplace to have an informational term entering into the fundamental laws of physics as a source of free energy."

"Information in life... amounts to much more than just playing the margins of the , and gaining some... energy advantage. ...I'm calling this a demonic cut. It's much more than just Shannon s at the thermodynamic level. Biological information is... contextual, or functional, or semantic. It depends upon the overall system."

"[A] is a set of instructions for ribosome to make a protein. If you look at the DNA sequence that codes for a gene, there's nothing that can tell you, at the sequence level, that if you look at a particular , that this is a bit of functional or coding or contextual information, and it's not just junk."

"[T]his is something that can't be defined locally. It's got to be defined globally, in the context of the system as a whole. ...[T]hat's a very difficult thing for physicists to cope with because we're used to formulating all our laws of physics as local laws, and not as global laws."

"I'm using this term demonic cut by analogy with the Cartesian cut..."

"[A]t what point does information, in the physics of matter, cease to just be a thermodynamic issue, and become much more of a control issue? ...[O]ne place ...is the . ...[H]ow did this come into existence?"

"If ever you want an example of going from physics to biology, it's the origin of the ."

"[T]here is... not just [some] new physical law, but a new kind of physical law. ...[W]hat kind of physical law? ...[O]ne idea that Sarah Walker and I have flirted with is state-dependent laws of information. ...[T]ake chess as an analogy ...If you had a modified game of chess in which the rules ...could be updated according to the state of play ...this opens the way to new forms of complexity and new forms of configuration."

"We want to know the transition zone between this demonic cut... from just Shannon] bits of information... to this more complex form of global, or contextual, or functional information. ...[H]azarding some guesses ...it might be a transition that would be measured by the integrated information, or... pathway complexity that Lee Cronin toyed with, or the breakdown of unitarity, if you think that this is associated in some way with the quantum classical transition."

"[C]osmological limits of agency... [W]hat's the best that the universe can do? There's about... 10100k bits of free energy out there. What could be achieved? ... [Egyptian pyramids have] been achieved... Maybe... astro-engineering... [T]ake a galaxy that's rotating clockwise and make it rotate anti-clockwise? ...I suspect ...maybe yes. ...[T]urn the expanding universe into a contracting universe? ...I'm sure the answer is no."

"I know of no theorem that tells you... the maximum amount of change that agency can achieve in the universe, and what interests me... is agency at the end of the universe. If you end up in , which has a temperature and a horizon entropy, can you do anything with... those thermal fluctuations? Can you mine them... to extract energy?"

"[[w:Particle detector|[P]article detectors]] in De Sitter space respond as if they are immersed in a bath of thermal radiation. However, the stress energy momentum tensor in De Sitter space is not that of thermal radiation. It's just a renormalization of the cosmological constant. So there's something a bit funny about the thermal nature of De Sitter space, and I've been interested in whether you can mine that thermal stuff..."

"[I]f you have a Maxwell demon or something like a Szilard engine in , could you use it, as Maxwell envisaged, to use information to extract energy from De Sitter space and... do... useful work? ...[Perhaps] only if you can create a region of the De Sitter space that is screened out from that horizon... from that thermal nature. If you put a reflective barrier around the demon, you then have De Sitter space, but with the horizon screened out. ...[T]hat's a problem I'm working on now ..."

"We should, of course, expect that any universe which expands without limit will approach the empty de Sitter case, and that its ultimate fate is a state in which each physical unit—perhaps each nebula or intimate group of nebulae—is the only thing which exists within its own observable universe."

"The general theory of relativity considers physical space-time as a four-dimensional manifold whose line element coefficients g_{\mu \nu} satisfy the differential equationsG_{\mu \nu} = \lambda g_{\mu \nu} \qquad .\;.\;.\;.\;.\;.\; (1)in all regions free from matter and electromagnetic field, where G_{\mu \nu} is the contracted Riemann-Christoffel tensor associated with the fundamental tensor g_{\mu \nu}, and \lambda is the ."

"An "empty world," i.e., a homogeneous manifold at all points at which equations (1) are satisfied, has, according to the theory, a constant Riemann curvature, and any deviation from this fundamental solution is to be directly attributed to the influence of matter or energy."

"In considerations involving the nature of the world as a whole the irregularities caused by the aggregation of matter into stars and stellar systems may be ignored; and if we further assume that the total matter in the world has but little effect on its macroscopic properties, we may consider them as being determined by the solution of an empty world."

"The solution of (1), which represents a homogeneous manifold, may be written in the form:ds^2 = \frac{d\rho^2}{1 - \kappa^2\rho^2} - \rho^2 (d\theta^2 + sin^2 \theta \; d\phi^2) + (1 - \kappa^2 \rho^2)\; c^2 d\tau^2, \qquad (2)where \kappa = \sqrt \frac{\lambda}{3}. If we consider \rho as determining distance from the origin... and \tau as measuring the proper-time of a clock at the origin, we are led to the de Sitter spherical world..."

"is a congruence geometry, or equivalently the space comprising its elements is homogeneous and isotropic; the intrinsic relations between... elements of a configuration are unaffected by the position or orientation of the configuration. ...[M]otions of are the familiar translations and rotations... made in proving the theorems of Euclid."

"[O]nly in a homogeneous and isotropic space can the traditional concept of a rigid body be maintained."

"That the existence of these motions (the "axiom of free mobility") is a desideratum, if not... a necessity, for a geometry applicable to physical space, has been forcefully argued on a priori grounds by von Helmholtz, Whitehead, Russell and others; for only in a homogeneous and isotropic space can the traditional concept of a rigid body be maintained."

"Euclidean geometry is only one of several congruence geometries... Each of these geometries is characterized by a real number K, which for Euclidean geometry is 0, for the hyperbolic negative, and for the spherical and elliptic geometries, positive. In the case of 2-dimensional congruence spaces... K may be interpreted as the ' of the surface into the third dimension—whence it derives its name..."

"[W]e propose... to deal exclusively with properties intrinsic to the space... measured within the space itself... in terms of... inner properties."

"Measurements which may be made on the surface of the earth... is an example of a 2-dimensional congruence space of positive curvature K = \frac{1}{R^2}... [C]onsider... a "small circle" of radius r (measured on the surface!)... its perimeter L and area A... are clearly less than the corresponding measures 2\pi r and \pi r^2... in the Euclidean plane. ...for sufficiently small r (i.e., small compared with R) these quantities on the sphere are given by 1):L = 2 \pi r (1 - \frac{Kr^2}{6} + ...), A = \pi r^2 (1 - \frac{Kr^2}{12} + ...)"

"In the sum \sigma of the three angles of a triangle (whose sides are arcs of s) is greater than two right angles [180&deg;]; it can... be shown that this "spherical excess" is given by 2)\sigma - \pi = K \deltawhere \delta is the area of the spherical triangle and the angles are measured in s (in which 180&deg; = \pi [radians]). Further, each full line (great circle) is of finite length 2 \pi R, and any two full lines meet in two points—there are no parallels!"

"[T]he space constant K... "" may in principle at least be determined by measurement on the surface, without recourse to its embodiment in a higher dimensional space."

"These formulae [in (1) and (2) above] may be shown to be valid for a circle or a triangle in the hyperbolic plane... for which K < 0. Accordingly here the perimeter and area of a circle are greater, and the sum of the three angles of a triangle are less, than the corresponding quantities in the Euclidean plane. It can also be shown that each full line is of infinite length, that through a given point outside a given line an infinity of full lines may be drawn which do not meet the given line (the two lines bounding the family are said to be "parallel" to the given line), and that two full lines which meet do so in but one point."

"The value of the intrinsic approach is especially apparent in considering 3-dimensional congruence spaces... The intrinsic geometry of such a space of curvature K provides formulae for the surface area S and the volume V of a "small sphere" of radius r, whose leading terms are 3)S = 4 \pi r^2 (1 - \frac{Kr^2}{3} + ...), V = \frac{4}{3} \pi r^3 (1 - \frac{Kr^2}{5} + ...)."

"In all these congruence geometries, except the Euclidean, there is at hand a natural unit of length R = \frac{1}{K^\frac{1}{2}}; this length we shall, without prejudice, call the "radius of curvature" of the space."

"We have merely (!) to measure the volume V of a sphere of radius r or the sum \sigma of the angles of a triangle of measured are \delta, and from the results to compute the value of K."

"What is needed is a homely experiment which could be carried out in the basement with parts from an old sewing machine and an Ingersoll watch, with an old file of Popular Mechanics standing by for reference! This I am, alas, afraid we have not achieved, but I do believe that the following example... is adequate to expose the principles..."

"Let a thin, flat metal plate be heated... so that the temperature T is not uniform... clamp or otherwise constrain the plate to keep it from buckling... [and] remain [reasonably] flat... Make simple geometric measurements... with a short metal rule, which has a certain coefficient of expansion c... What is the geometry of the plate as revealed by the results of those measurements? ...[T]he geometry will not turn out to be Euclidean, for the rule will expand more in the hotter regions... [T]he plate will seem to have a negative curvature K... the kind of structure exhibited... in the neighborhood of a ".""

"What is the true geometry of the plate? ...Anyone examining the situation will prefer Poincaré's common-sense solution... to attribute it Euclidean geometry, and to consider the measured deviations... as due to the actions of a force (thermal stresses in the rule). ...On employing a brass rule in place of one of steel we would find that the local curvature is trebled—and an ideal rule (c = 0) would... lead to Euclidean geometry."

"In what respect... does the general theory of relativity differ...? The answer is: in its universality; the force of gravitation in the geometrical structure acts equally on all matter. There is here a close analogy between the gravitational mass M...(Sun) and the inertial mass m... (Earth) on the one hand, and the heat conduction k of the field (plate)... and the coefficient of expansion c... on the other. ...The success of the general relativity theory... is attributable to the fact that the gravitational and inertial masses of any body are... rigorously proportional for all matter."

"The field equation may... be given a geometrical foundation, at least to a first approximation, by replacing it with the requirement that the mean curvature of the space vanish at any point at which no heat is being applied to the medium—in complete analogy with... the general theory of relativity by which classical field equations are replaced by the requirement that the Ricci contracted curvature tensor vanish."

"Now it is the practice of astronomers to assume that brightness falls off inversely with the square of the "distance" of an object—as it would do in Euclidean space, if there were no absorption... We must therefore examine the relation between this astronomer's "distance" d... and the distance r which appears as an element of the geometry."

"All the light which is radiated... will, after it has traveled a distance r, lie on the surface of a sphere whose area S is given by the first of the formulae (3). And since the practical procedure... in determining d is equivalent to assuming that all this light lies on the surface of a Euclidean sphere of radius d, it follows...4 \pi d^2 = S = 4 \pi r^2 (1 - \frac{K r^2}{3} + ...);whence, to our approximation 4)d = r (1- \frac{K r^2}{6} + ...), or r = d (1 + \frac{K d^2}{6} + ...)."

"[T]he astronomical data give the number N of nebulae counted out to a given inferred "distance" d, and in order to determine the curvature... we must express N, or equivalently V, to which it is assumed proportional, in terms of d. ...from the second of formulae (3) and... (4)... to the approximation here adopted, 5)V = \frac{4}{3} \pi d^2 (1 + \frac{3}{10} K d^2 + ...);...plotting N against... d and comparing... with the formula (5), it should be possible operationally to determine the "curvature" K."

"This... is an outrageously over-simplified account of the assumptions and procedures..."

"The search for the curvature K indicates that, after making all known corrections, the number N seems to increase faster with d than the third power, which would be expected in a Euclidean space, hence K is positive. The space implied thereby is therefore bounded, of finite total volume, and of a present "radius of curvature" R = \frac{1}{K^\frac{1}{2}} which is found to be of the order of 500 million light years. Other observations, on the "red shift" of light from these distant objects, enable us to conclude with perhaps more assurance that this radius is increasing..."

"It was the work of... Friedmann, Robertson and Walker, which resulted in the general mathematical framework that is still used today when discussing relativistic cosmological models of a homogeneous and isotropic universe."

"[I]nvestigations of cosmological issues, whose only observational basis was the observations. ...involved ...mostly of mathematicians like Howard Robertson and and astronomers with strong mathematical training such as Eddington, Lemaître, George McVittie, and William McCrea. They were mainly interested in how to apply general relativity to cosmological problems, which involved not only understanding cosmic dynamics but also solving the intricate problem of interpreting cosmological solutions to the Einstein equations, in particular separating time (which determined the evolution of the universe) from space (to which simplified assumptions concerning the structure of the universe, such as homogeneity and , were to be applied)."

"Distinguished scientist, selfless servant of the national interest, courageous champion of the good and the right, warm human being, he gave richly to us and to all from his own great gifts. We are grateful for the years with him. We mourn the loss of his presence but rejoice in the legacy of his wisdom and strength."

"Weyl published a third appendix to his Raum, Zeit, Materie, and an accompanying paper], where he calculated the redshift for the ‘de Sitter cosmology’,ds^2 = -dt^2 + e^{2{\sqrt{\frac{\Lambda}{3}t}}} (dx^2+dy^2+dz^2),the explicit form of which would only be found later, independently by Lemaître and Robertson."

"The basic cause and nature of cosmic expansion, along with its recently-observed acceleration, are significant problems of the standard model; so, condisering the evidence that the acceleration is best described by pure \Lambda, there is strong motivation to search for an alternative big bang model that would respect the pioneering concept of expansion, as a direct consequence of the ‘de Sitter effect’ in the modified . It is therefore worth investigating the axiomatic basis of the Robertson-Walker (RW) line-element."

"[I]n deriving the general line-element for the background geometry of FLRW [Friedmann–Lemaître–Robertson–Walker, sometimes called the Standard Model] cosmology, Robertson required four basic assumptions: i. a congruence of s, ii. , iii. homogeneity, and iv. . i. and ii. are required to satisfy of a causal coherence amongst s in the entire Universe, by which every single event in the bundle of fundamental world lines is associated with a well-defined three-dimensional set of others with which it ‘really’ occurs simultaneously. However, it seems that ii. is therefore mostly required to satisfy the concept that synchronous events in a given inertial frame should have occurred simultaneously, against which I’ve argued..."

"Note.—The second part of this paper was considerably altered by me after the departure of Mr. Rosen for Russia since we had originally interpreted our results erroneously. I wish to thank my colleague Professor Robertson for his friendly in his assistance in the clarification of the original error."

"Important contributions to what would later appear as mainstream big bang cosmology were made by Americans Howard P. Robertson and Richard Tolman... Robertson (and independently, A. G. Walker in England) deduced in 1935 the most general form of the metric for a space-time satisfying the : the postulate that the universe is spatially homogeneous in its large scale appearance. This metric became generally known as the Robertson-Walker metric. Together with Tolman, Robertson pioneered the study of thermodynamics in the theory of the expanding universe."

"Many of the theoretical investigations of cosmology in the 1920s were examinations of De Sitter's model, which is particular because it can be understood both as a static model (as De Sitter did) and as an expanding model (as became the view after 1930). It is clearly problematic to read the pre-1930 literature in light of later knowledge. 'Expanding' versions of the De Sitter universe were found by in 1922, Hermann Weyl in 1923, and Lemaître in 1925, but were not conceived as expanding in any real sense. These works, as well as later works by Howard Percy Robertson and Richard Chase Tolman in the United States, consisted in transforming De Sitter's line element in such a way that it formally became static, that is, included a term F(t) referring to the time parameter. The metric, giving the distance in space-time between two neighboring points, would then be in the form ds^2 = c^2 dt^2 - F(t)(dx^2 = dy^2 +dz^2)."

"In 1928 Robertson found a non-static line element similar to the one Lemaître had found three years earlier. Also like Lemaître, he derived a linear relationship between apparent recessional velocities and distances, and he discussed it in relation to observation data. Within the same tradition was Tolman's 1929 derivation of a 'Hubble law', that is, a relationship of the form v = kr, with v = \frac{d\lambda}{\lambda}. Robertson and Tolman generalized the De Sitter model to an arbitrary scale factor F(t), but they remained within the static paradigm and did not realize the significance of F(t). In a paper of 1929, Robertson wrote the general line element of what would later be known as the Robertson-Walker models and he even referred to Friedmann's work. And yet, although he had evidently studied Friedmann, he 'misread' him and failed to realize the significance of the expanding metric."

"Robertson and Tolman developed much of the mathematics of the expanding universe, but without concluding or predicting prior to 1930 that the universe actually expands. They were not discoverers or codiscoverers of the expanding universe (and never claimed that they were)."

"Howard Percy Robertson was a postdoctorate student at Göttingen and Munich from 1925 to 1927. While in Göttingen he completed an important paper on relativistic cosmology in which he derived a relation between the velocity of nebulae and their distances. For the radius of the observable world he calculated R = 2 \times 10^{25} m. Although he had a velocity-distance relation and referred to Slipher's s, he did not conclude that the universe was in a state of expansion."

"Robertson wrote an influential [1933] review of relativistic world models in which he specifically excluded those which have "arisen in finite time from the singular state R = 0." Although he included the Einstein-de Sitter paper in his bibliography, he did not mention it in the review. He also did not mention Lemaître's primeval-atom hypothesis."

"Howard P. Robertson showed that the uncertainty relation follows from the commutation rule."

"As Daniel Dennefink explains in his article on the story behind the writings of the Einstein-Rosen gravitational paper, the singularity that Einstein and Rosen had encountered was an apparent singularity introduced by their choice of coordinate system, similar to the singularity one encounters when attempting to find the longitude of the North Pole. In fact, in his referee report Robertson had indicated that the singularity was removed by a change to a cylindrical coordinate system."

"In June 1936, Einstein and Rosen sent the paper... "Do Gravitational Waves Exist?" to The Physical Review... [which] rejected the paper, provoking Einstein's furious reaction. Einstein told the editor he... saw no reason to address the erroneous comments of his anonymous expert [Howard Percy Robertson] and... preferred to publish the paper elsewhere. ...Leopold Infeld arrived in Princeton to replace Rosen as... assistant. Einstein explained to him his proof of the non-existence of gravity waves. ...Infeld told Robertson [then professor of theoretical physics at Princeton] about Einstein's... paper[.] Robertson... found a trivial mistake [by] Infeld [and] clarified... the mistake in Einstein's explanation... The linearized approximation [led] to plane transverse gravitational waves... introduc[ing]... coordinate singularities... not real singularities. ...Robertson ...suggested ...the so-called Einstein-Rosen metric... be transformed... to cylindrical coordinates. ...the singularity can be regarded as describing a material source. The solution describe[s]...cylindrical... rather than plane gravitational waves. ...with Robertson's help (still not knowing it was Robertson who had [refereed] The Physical Review) ...Einstein ...revis[ed the] ...paper and added a section: "Rigorous Solution for Cylindrical Waves"... The new version of the paper was re-titled "On Gravitational Waves"..."

"I have too much respect for God to make it a scientific hypothesis."

"I was interested in truth from the point of view of salvation just as much as in truth from the point of view of scientific certainty. It appeared to me that there were two paths to truth, and I decided to follow both of them."

"The primaeval atom"

"We want a fireworks theory of evolution. The last two thousand million years are slow evolution: they are the smoke and ashes of bright but very rapid fireworks."

"There is no conflict between science and religion."

"In a previous paper we showed that a static (nonrotating) black hole cannot be endowed with exterior scalar-meson or massive vector-meson fields. Here we show that the same is true for massive spin-2 meson fields. We also extend the above results to the case of a rotating stationary black hole. We conclude from our results that a black hole in its final (static or stationary) state cannot interact with the exterior world via the strong interactions which are mediated by meson fields such as the π (scalar), ρ (vector), and ƒ (spin-2). A direct consequence of this is the impossibility of determining the baryon number of the black hole by means of exterior measurements alone. This results in the transcendence of the law of baryon-number conservation as originally predicted by Wheeler."

"We show that it is natural to introduce the concept of black-hole entropy as the measure of information about a black-hole interior which is inaccessible to an exterior observer. Considerations of simplicity and consistency, and dimensional arguments indicate that the black-hole entropy is equal to the ratio of the black-hole area to the square of the Planck length times a dimensionless constant of order unity. A different approach making use of the specific properties of Kerr black holes and of concepts from information theory leads to the same conclusion, and suggests a definite value for the constant."

"Black holes set a limitation on the number of species of elementary particles—quarks, leptons, neutrinos—which may exist. And black holes lead to a fundamental limitation on the rate at which information can be transferred for given message energy by any communication system."

"The DM halo hypothesis is evidently an attempt to resolve the acceleration discrepancy within orthodox gravitation theory. But in coming to terms with this discrepancy, suspicion fell on Newtonian gravity already early in the game. Zwicky, who had exposed the acceleration discrepancy in clusters of galaxies ..., opined much later that the discrepancy may reflect a failure of conventional physics ..."

"Within the DM paradigm the Tully-Fisher law must arise from galaxy formation since it connects luminosity of baryonic matter with a dynamical property, rotation, which is seen as dominated by the DM halo. But it has not been easy to derive Tully-Fisher from any natural connection between the two components. And as R. H. Sanders has pointed out, the messiness of galaxy formation is hardly the natural backdrop for such a sharp correlation between galaxy properties. The sharpness needs a dynamical reason as opposed to an evolutionary one."

"There is a prescription that works well, MOND, but the reason it works so well is not known. You may say that MOND tells us how the real theory of gravity should look."

"Bekenstein incorporated black hole entropy into a generalized second law—that the sum of the entropy outside black holes plus the newly proposed entropy of black holes must never decrease—and carefully considered processes that might violate it. To avoid violations, he found that he had to assume limitations on how close to the black hole’s horizon one could lower matter. Those ideas eventually evolved into a proposal for a bound on the entropy-to-energy ratio of matter confined to a region of given size."

"Jacob was the first physicist to hear from me about MOND. It was 1982; Jacob was still at Ben Gurion University in Beer Sheba. I went there from Rehovot with my initial MOND trilogy of preprints in my bag to tell Jacob and benefit from his advice. I had not prepared him for what was in these preprints. Jacob was immediately captured, but he also warned me — as I vividly remember — that this is going to encounter much opposition, but also that I should not heed such opposition. He was drawing on his own experience with black-hole entropy and on how his ideas had been received a decade earlier."

"If you want to rely on non-empirical assessment, you have to make really sure that scientists’ judgment is as objective as humanly possible. And the environment in academia presently is absolutely unsuitable for this. You just can’t be sure how much sociology affects judgment. And no physicist I know makes any effort to consciously address cognitive biases, such as wishful thinking, loss aversion, or the use of aesthetic criteria. It’s just not something that they pay attention to because it’s never been necessary before. As long as you have data for guidance, you’ll be swiftly corrected."

"To make predictions with inflation one cannot just say “there once was exponential expansion and it ended somehow.” No, to be able to calculate something, one needs a mathematical model. The current models for inflation work by introducing a new field – the “inflaton” – and give this field a potential energy. The potential energy depends on various parameters. And these parameters can then be related to observations. The scientific approach to the situation would be to choose a model, determine the parameters that best fit observations, and then revise the model as necessary – ie, as new data comes in. But that’s not what cosmologists presently do. Instead, they have produced so many variants of models that they can now “predict” pretty much anything that might be measured in the foreseeable future."

"In our search for new ideas, beauty plays many roles. It's a guide, a reward, a motivation. It's also a systematic bias."

"The Standard Model is based on a principle called "gauge symmetry". According to this principle, every particle has a direction in an internal space, much like the needle in a compass, except that the needle doesn't point anywhere you can look."

"The logic of arguments from naturalness resembles the attempt to predict the plot of a long-running TV series. If the hero -- here, naturalness --is in a pickle, certainly he will survive, so something must happen to turn around a situation that looks bleak."

"if you pile up enough of it, even shit can look beautiful."

"The vacua with positive cosmological constant trap the universe in eternal inflation. They decay only locally, by producing bubbles of new vacua. Thus, every vacuum in the landscape will be realized an infinite number of times in different, causally disconnected regions. Each bubble expands to become an infinite open universe embedded in the global spacetime."

"There are 10500 or more metastable vacua, which can be thought of as local minima in a huge, multidimensional potential landscape. They differ not only in the value of their vacuum energy, but in their entire low-energy effective field theory, which is determined by local properties near the foot of a valley and thus only very indirectly by the fundamental building blocks of the landscape. Different vacua will have different matter content, coupling constants, and forces. We will not predict the standard model uniquely. We will have to predict many of the features of our universe statistically, from their relative abundance in the landscape."

"If gravity is a fundamental force, then it has to be explained by an expanded version of general relativity, a more complete, a more fundamental theory. Whether that is quantum gravity of something more radical that requires a paradigm shift like, for instance, our research in multiverse theory, nobody knows at the moment."

"You can vary Newton's constant and the fine-structure constant, which is responsible for the strength of electromagnetic interactions ... by six orders of magnitude, by thousands, and still get a universe that allows for life."

"I regret the time I have been eating instead of being in pursuit of learning - for time is precious."

"My heart was never deprived of science, There are little of the mysteries that I did not understand. For 72 years I thought night and day, Yet I came to know that nothing is to be known.”"

"It is established by evidence that there exists beyond the world a void without a terminal limit (khala' la nihayata laha), and it is established as well by evidence that God Most High has power over all contingent beings (al-mumkinat ). Therefore He the Most High has the power (qadir ) to create a thousand thousand worlds (alfa alfi 'awalim) beyond this world such that each one of those worlds be bigger and more massive than this world as well as having the like of what this world has of the throne (al-arsh), the chair (al-kursiyy), the heavens (al-samawat ) and the earth (al-ard ), and the sun (al-shams) and the moon (al-qamar ). The arguments of the philosophers (dala'il al-falasifah) for establishing that the world is one are weak, flimsy arguments founded upon feeble premises."

"The n-point correlation functions have proved useful not only as descriptive statistics but also as dynamic variables in the Newtonian theory of the evolution of clustering. ... The functions are generalized to mass correlation functions in position and momentum, and the BBGKY hierarchy of equations for their evolution is derived. This yields a new way to analyze the evolution of mass clustering in an expanding universe."

"A solid stores energy in the vibrations of the atoms about their equilibrium positions. In the simplest approximation, which Einstein considered, each atom vibrates with the same frequency, ν, in each of three dimensions, so a solid containing N atoms can be thought of as 3N one-dimensional simple harmonic oscillators."

"Another somewhat confusing usage is the name "the big bang" for the standard model. It is not appropriate, because it connotes a spatially isolated event, an explosion, that marked the start of everything. ... But the name has a very evident appeal and I expect that people will continue to use it."

"I have been working in cosmology for 55 years ... I'm the last man standing, so to speak, from those early days."

"I don't think there is a final theory of anything. It's theories all the way down."

"Don't pay too much attention to that Nobel Prize. They have to be capricious — they have to be. And that means that people fully deserving the award don't get it."

"If dark matter is in the form of stellar mass compact objects, then the extremes of such variability are accessible to a monitoring campaign with the Hubble Space Telescope. With the advent of the Next Generation Space Telescope, cluster dark matter in the form of compact objects will induce a ubiquitous ‘shimmering’ of the giant arcs."

"If planetary systems are ubiquitous then a fraction of stars should possess a transiting planet when being microlensed. ... For the giant planets recently identified, the deviations in the light curve can be substantial, although the specifics of the perturbations are dependent upon the radius of the planet relative to that of the star, the location of the planet over the stellar surface and the orientation of the sweeping caustic. Given that the instantaneous probability of transiting hot-Jupiter like planets is small, less than a percent, and only a proportion of microlensing events exhibit caustic crossing events, the probability of detecting a transiting planet during a microlensing event is small, ~10-6. However, a number of factors influencing this probability, such as the number of solar type star that possess planets, are uncertain, and the prospect of detecting transiting planets in future large catalogues of microlensing light curves may be viable."

"What has led astronomers and cosmologists to come to this picture we have of this expanding universe that started in the big bang?"

"[The] transformation of the blind course of nature into one that is rational [...] is bound to appear to the learned as a disruption of order, although this order of theirs brings only disorder among men, striking them down with famine, plague, and death."

"How unnatural it is to ask, ‘Why does that which exist, exist?' and yet how completely natural it is to ask, ‘Why do the living die?"

"The learned, who have fragmented science into a multiplicity of branches, imagine that the calamities that strike and oppress us are within the competence of specialised disciplines to control, whereas in fact they constitute a single problem common to all of us, namely the lack of kinship relations between a blind force and rational beings. This blind force makes no demand on us other than to endow it with what it lacks: rational direction, or regulation. Yet no regulation is possible owing to our disunity, and our disunity persists because there is no common task to unite men. Regulation, the control of the blind force of nature, can and must become the great task common to us all."

"A truly moral being does not need compulsion and repeated orders to perceive what his duty is – he assigns to himself his task and prescribes what must be done for those from whom he has become separated, because separation (whether voluntary or not) cannot be irreversible. Indeed, it would be criminal to repudiate those from whom one descends and to forget about their welfare. For the learned to behave thus would be to reject their own welfare, to remain prodigal sons for ever and be permanent hirelings and servants of urban caprice. This would lead them to disregard completely the needs of rural communities, that is, real needs, because the needs of such communities, unspoilt by city influences, are limited to those essentials that ensure survival in the face of hunger and illness, which not only destroy life but also displace kinship relations and replace love by enmity and hostility."

"[T]he rural problem is (1) loss of kinship between men who, through ignorance, forget their relatedness, and (2) the hostility of nature to humans, which is felt most acutely if not exclusively in villages, where people confront the blind force directly; whereas townsfolk, being remote from nature, may think that man lives at one with nature."

"Only when all men come to participate in knowledge will pure science, which perceives nature as a whole in which the sentient is sacrificed to the insensate, cease to be indifferent to this distorted attitude of the conscious being to the unconscious force."

"To admit an absence of causality for the unbrotherly state leads not to peace and brotherhood but merely to playing at peace, to a comedy of reconciliation which creates a pseudo-peace, a false peace which is worse than open hostility because the latter poses a question whereas the former prolongs enmity by concealing it."

"The problem of the force which brings the two sexes to unite and give birth to a third being is also a problem of death."

"Internal discord reflects external disunion, that is, the separation of the learned and intellectual classes from the people. Intelligence without feeling becomes the knowledge of evil without any desire to root it out, and a knowledge of good without any wish to promote it. It is an admission of lack of kinship and not a plan to re-establish kinship bonds. The consequence of indifference is oblivion for the fathers and discord among the sons. The causes of lack of kinship extend to nature as a whole, for it is a blind force uncontrolled by reason."

"The principle of disunion and inactivity informs all three Critiques. The philosophy of art which he embodies in his Critique of Judgement does not teach how to create, but only how to judge the aesthetic aspects of works of art and of nature. It is a philosophy for art critics, not for artists and poets. In the Critique of Judgement, nature is regarded not as an object to be acted upon and transformed from a blind force into one governed by reason, but merely as an object of contemplation to be judged on its aesthetic merits; not from the point of view of morality, which would recognise it as destructive and death-bearing..."

"Our task is to make nature, the forces of nature, into an instrument of universal resuscitation and to become a union of immortal beings. The problem of God's transcendence or immanence will only be solved when humans in their togetherness become an instrument of universal resuscitation, when the divine word becomes our divine action."

"The grief of a son mourning the death of his father is truly universal, because death as a law (or, rather, an inevitable hazard) of blind nature could not fail to arouse intense pain in a being who has attained consciousness, and who can and must achieve the transition from a world dominated by this blind force of nature to a world governed by consciousness, and where there is no place for death. This universal grief is both objective because of the universality of death and subjective because mourning a father's death is common to all. Truly universal grief is the regret for having been lacking in love for the fathers, and for one's own excessive self-love. It is sorrowing for a distorted world, for its fail, for the estrangement of sons from fathers and of consequences from causes."

"Universal Christian grief is the sorrowing over disunity (that is, over enmity and hatred and their ensuing consequences such as suffering and death), and this sorrow is repentance; it is something active that includes hope, expectation and trust. Repentance is the recognition of one's guilt over disunity and of one's duty to work for unification in universal love in order to eliminate the consequences of disunity."

"The minorship of the human race is nowhere more evident than in the superstitious veneration of everything natural, the acceptance of the supremacy of blind nature over intelligent beings (natural morality). It is not the savages who are in this state of childishness and minority, not young nations, but the ageing ones which do not notice their superstitions and even pride themselves on being free from superstition. This happened in ancient history, it is happening now, and this state of childishness usually begins during the era of a nation's decline, though the nation believes itself to be at the zenith of its civilisation. The present puerility of Western Europe is a form of paganism, though secularised since the era of the so-called Renaissance. Death is venerated too, as being natural."

"Nature is regarded as a death-bearing, self-destructive force, but not because of its blindness. Yet where can a blind force lead except to death? Humans admit nature to be a blind force even when they regard themselves as part of it and accept death as a kind of law and not as a mere accident which has permeated nature and become its organic vice. Yet death is merely the result or manifestation of our infantilism, lack of independence and self-reliance, and of our incapacity for mutual support and the restoration of life. People are still minors, half-beings, whereas the fulness of personal existence, personal perfection, is possible. However, it is possible only within general perfection. Coming of age will bring perfect health and immortality, but for the living immortality is impossible without the resurrection of the dead."

"History as fact is mutual extermination, the extermination of people like ourselves, the pillage and plunder of nature (that is, the Earth) through its exploitation and utilisation, leading to degeneration and dying (culture). History as fact is always mutual extermination, either overt in times of barbarism or covert in times of civilisation, when cruelty is merely more refined and even more evil. This situation raises the question: must man be the exterminator of his own species and the predator of nature, or must he be its regulator, its manager, and the restorer to life of his own kin, victims of his blind unruly youth, of his past – that is, of history as fact?"

"By using the mass of Earth and transforming it into conscious force, the united human race will give to the telluric force, controlled by reason and feeling — that is, by a life-giving force — domination over the blind force of other celestial bodies, and will involve them in a single life-giving force of resuscitation."

"Apart from a slowly advancing end, we cannot be certain whether a sudden catastrophe may not befall the Earth, this tiny grain of sand in the vastness of the Universe."

"If, however, progress is the transformation of the spontaneous (procreation) into conscious work, we must regard parasites as an inherent evil. The control method used is undoubtedly immoral, since it takes advantage of the natural evil of an epidemic. Nor can the annihilation of any insect be considered moral. Only the complete transfiguration of a blind force (procreation) into a conscious act can be called moral."

"Man placed himself at the mercy of fate (that is to say, the annual rotation of the Earth), he submitted to the Earth; childbirth replaced the artistry of reproducing oneself in other beings, a process comparable to the birth of the Son from the Father, or the procession of the Holy Ghost. Later, proliferation increased the struggle, which was fostered by an unbridled surge of procreation; and with the increase in birth, mortality increased too. The conditions which could have regulated this concatenation of phenomena disappeared, and gradually there came revolutions, storms, drought and earthquakes; the solar system became an uncontrolled world, a star with an eleven-year cycle or some other periodicity of various catastrophes. Such is the system we know. One way or another, to confirm us in our knowledge, the solar system must be transformed into a controlled economic entity."

"What will nature — which, in its present, unconscious state, is a force that procreates and kills - become when it achieves consciousness, if not a force restoring what it has destroyed in its blindness ? How senseless are statements about the incommensurability of the forces of man, that is, of nature striving towards consciousness and control, and the forces of the same blind nature. And should one term 'human force' merely that of man's own hand, or include what he can achieve through nature ? And are human force and human activity to be limited to what man achieves now by using the forces of nature ? Why, the true, the natural task has not even begun..."

"Contrary to Schopenhauer's 'world as will and representation', it should be 'world as slavery and the project of liberation from enslavement', from dependence, from subordination to a blind force; for us the world has no will, and for beings endowed with feeling and capable of action and not mere contemplation, the world is not solely a representation but a project of liberation from bondage. The expression 'the world as will and representation' could be justifiably replaced by the expression 'the world as lust', for lust procreates and kills, giving birth to sons and destroying the fathers. For us the world is not a representation but a project, moreover one that does not oppose lust (the opposite of lust is asceticism) but transforms the procreating force into a re-creating one, the lethal into a vivifying. Then the world can no longer remain a representation but becomes a project of the restoration of the predecessors by the offspring, that is, a project of resuscitation. That is how it should be, but at the present time the world is as it is — lust and representation."

"The will to procreate, as lust, engenders wealth and leads the human race to demoralisation (of which the Universal Exhibition is a striking expression), whereas the will to resuscitate, when the problem of returning life is seen as the purpose of conscious beings, moralises all the worlds of the Universe, because then all the worlds that are moved by insensate forces will be governed by the brotherly feelings of all the resurrected generations. This involves both their moralisation and their rationalisation, because then the worlds of the Universe will no longer be moved by blind insensate forces but will be governed by the feelings and reason of the resurrected generations."

"Be perfect as God your Father is perfect, God the Father of the living, not of the dead. Where should we look for models of living? In the world of the animals, of blind nature, or in a world that is superior to the human race? Should the model for our society be an organism and the blind evolution of life, or should the model for our unity-in-pluralism be the Divine Trinity, within which unity is not a yoke and independence not discord? Would not then Divine creativeness, replacing our present destruction of life, serve us as a model for its re-creation?"

"[A]utocracy is the task of the sons which becomes, with the full union of those sons, the return of life to the dust of the fathers – that is to say, struggle not against members of our own species but against the dark force which procreates and destroys life."

"To abdicate the task of resuscitation leaves the human race only the choice between constitutional debating and despotism. To retain Easter as a feast only and the liturgy as a church service, an expression of an as yet incomplete love for the fathers which does not entail actual resuscitation, or, by abdicating completely brotherhood and filial love, to indulge on the graves of the fathers in bestial orgies followed by savage mutual extermination; to retain the art of dead likenesses or to annihilate any true likenesses; not merely to censure parents for giving life to their offspring without their consent, but to curse one's procreators; to retain academic class science or, rejecting all knowledge, to descend into the hopeless darkness of obscurantism; to remain in the perennial city of brides and bridegrooms, surrounded by toys and trifles, indulging in pleasures and entertainments, or else, rejecting not only fathers and forebears but even progeny, sons (artificially childless marriages), in order to indulge in boundless lechery; to retain will as either lust or mortification of the flesh; to retain sensuousness or to be satisfied by mere grieving for the dead or — the last and greatest evil — to plunge into nirvana, the product of total evil negation — such are the fruits of abdicating the task of resuscitation."

"Negative virginity is not yet a celestial virtue; chastity is not yet active wisdom; not to beget is not yet liberation from death — resurrection. It is essential that unconscious procreation be replaced by the task of resuscitation."

"When external regulation has been achieved, the inner psychophysiological force will tilt the balance away from sexual drive and lust towards love for the parents, and will even replace them, thus transforming the force of procreation into one of re-creation, the lethal into a vivifying force; in other words, childbirth will be replaced by patrification, in fulfilment of the will of the God of the fathers."

"[T]he present generation is too frightened by the magnitude of time and space revealed by geology and astronomy, and has been so conditioned by four centuries of nature worship that it feels only its insignificance, and fears even to contemplate such an endeavour as weather control."

"[M]an has always felt and recognised the imperfection of nature, and has never accepted it as law. He broke this law when he took his first step, because his vertical posture challenged gravity, the most universal law of nature. This upright position is not natural to man – it is supranatural – and he has achieved it artificially, through effort (by swaddling and other methods of adaptation). One cannot say of man that he is the creation of nature. On the contrary, he is the result of under-creation, of deprivation, of a natural pauperism which is shared by rich and poor alike; he is a proletarian, a pariah among living creatures. Yet in this lay the origin of his future greatness; deprived of natural cover and means of defence, he had to create all this himself by his own labour. Therefore man values only that which has been created by working, or which expands the area of application of work; it is not difficult to guess that the culmination of this forward movement must be that everything on which human life depends will ultimately be achieved through work, so that humans will depend solely on their labour. Consequently the entire world, the meteorological, telluric and cosmic processes, will be the responsibility of man, and nature will be his work. Man is driven towards this goal by hunger, disease and every other calamity, so that whenever he delays in expanding the area of work, the scope for disasters expands. Thus nature punishes man by death for his ignorance and sloth, and drives him to ever-expanding labour."

"Before talking about resurrection one must state firmly that, just as death is impossible where there exist sinlessness and knowledge that can control the forces of nature, so resurrection is impossible where there exist sin, ignorance and other misfortunes resulting from man's dependence on the blind forces of nature."

"Neither the universal return to life, universal resurrection, nor even death itself, have hitherto been the subject of knowledge or well founded judgement. For there would have been full, detailed investigations into the reasons and conditions that have given rise to the phenomenon. For most people, death appears to be an absolute, inevitable phenomenon; but just how unfounded is this conclusion is obvious from the fact that it is considered acceptable to talk about the opposite of death, about immortality, and even about resurrection; and it is talked about as a possibility, in circumstances where all sorts of sins prevail among people, and all sorts of calamities and evils, arising from the folly of nature. But if the coexistence of the one with the other is unthinkable, since the one excludes the other, then can one talk about the possibility of death where there is moral and physical sinlessness, where nature shows such a benign attitude both within and outside man, of the sort that is deemed possible when man's knowledge and control of nature are complete?"

"To solve the question, 'What should art be?' will be to solve the contradiction between rational being and the blind force of nature, to fathom the most abnormal relationship between man and nature, to solve the question of the subordination of rational being to blind force. Will nature always remain blind and, in its blindness, a destructive force, while art remains the creation of nothing but dead imitations? Will this division be temporary, or will it last for ever? Perfection lies in the unity of nature and art."

"Nature, within man, was conscious of the evil of death, of its own imperfection. So the rebellion of the living (the vertical posture) and the resurrection of the dead, in the form of tombstones, are natural acts for a feeling, rational being. It was when the living (who had suffered a loss) rebelled and turned to heaven, and when the dead were resurrected in the form of tombstones, that art began. Prayer was the beginning of art. Prayer and the (vertical) prayer posture constituted the first acts of art; this was theo-anthropurgic art, which consisted of God creating man through man himself. For man is not only a product of nature but also a creation and concern of art. The last act of divine creation was the first act of human art, for man's purpose is to be a free being and consequently self-created, since only a self-created being can be free. In this act of self-creation – that is, in rebelling and turning towards heaven – man discovers God and God reveals himself to man; or, more precisely, on discovering the God of the fathers, the being who has made the discovery becomes not just a man, but a son of man. And only in the abstract sense, forgetting the loss, is it possible to say that the being which has discovered God has become man."

"If the question, 'What has art become?', is synonymous with 'What are the reasons for the unbrotherliness between people and for the rift in the relations between nature and people?' then the question, 'What should art be?' is the same as the problem of establishing brotherly unity in order to transform the blind force of nature into a force guided by the reasoning powers of all the resurrected generations. In other words, what we are talking about is universal resurrection, since it is this that represents the complete restoration of kinship and that will provide art with the appropriate course to follow, and show it its goal. Transforming all the worlds into worlds guided by the reasoning powers of resurrected generations will constitute a complete resolution of the Copernican question and is at the same time identical to the primeval view – that is, the patrification of the heavens (the turning of the heavens into the fathers' abode), or catasterisation (the transferral of the fathers' souls to the stars) – which also finds its expression in church sculpture and painting. For children this primeval view is the most straightforward, an explanation and resolution of the Copernican question. To turn all the worlds into worlds guided by the reasoning powers of resurrected generations is also the most important goal of art."

"Till now consciousness, reason and morality were localised on planet Earth; by resurrecting all the generations who have lived on this Earth, consciousness will be disseminated to all the worlds of the Universe. Resurrection is the transformation of the Universe from that chaos towards which it is moving into cosmos — into the greatness of incorruptibility and indestructibility."

"In the past few years the search for a consistent quantum theory of gravity and the quest for a unification of gravity with other forces have led to a great deal of interest in theories with extra spatial dimensions. These extra spatial dimensions are unseen because they are compact and small, presumably with typical dimensions of the Planck length, lPl = 1.616 × 10-33 cm. If the “internal” dimensions are static and small compared to the large “external” dimensions the only role they would play in the dynamics of the expansion of the Universe is in determining the structure of the physical laws. However, if the big bang is extrapolated back to the Planck time, then the characteristic size of both internal and external dimensions were the same, and the internal dimensions may have had a more direct role in the dynamics of the evolution of the Universe."

"We live in a hot, expanding Universe. We also live in a Universe that on 'large' scales is homogeneous, the same at every point, and isotropic, the same in every direction. There is an ample (and growing) body of evidence for homogeneity and isotropy. The isotropy and homogeneity of the Universe is the most fundamental principle in modern cosmology. In fact, it is called the Cosmological Principle."

"The precision cosmological measurements have lead to the latest cosmological model, usually called the standard cosmological model, or ΛCDM, where Λ indicates Einstein’s cosmological constant (or more generally, dark energy), and CDM stands for cold dark matter. ... The most remarkable feature of the standard cosmological model is that it seems capable of accounting for all cosmological observations; i.e., it seems to work!"

"Leon and I used to tease each other, because he's an experimentalist and I'm a theorist. And experimentalists are jealous of theorists, because theorists are smarter."

"Thus, even now, three and a half centuries after Galileo... it is still remarkably difficult to say categorically whether the earth moves..."

"In fact, I once had a discussion with a distinguished astrophysicist who said to me, well, this is what Mach said, and this is what Mach did and what he required. And I said to him, now excuse me, if you don't mind me saying, what you've just told me is your interpretation of Dennis Sciama's interpretation of Einstein's interpretation of Mach. And he said you're quite right. I’ve never read a word of Mach."

"(quote at 14:08 of 1:54:14)"

"[[Time|[T]ime]] is really an illusion... and motion too... [T]hey are not really there in the external world. They are put into the world by us, in the way we interpret it, and by our brains..."

"If you could freeze the camera now and... show me as I am, and all the atoms... and... the whole universe... like a snapshot, the would be... a NOW."

"If you could look microscopically... at... my molecules... you would not recognize me from one second to another. In my body, every second, one hundred million million million... hemoglobin molecules... is destroyed, and the same number is created. So... at each split second, I'm really a very different person."

"[T]he work that I did with... has shown... time that is measured by clocks is... an average of all the changes in the universe."

"[I]f you imagine two NOWs... there will be some difference between them, and if you work out some weighted average of all of that difference... you can call that... the amount of time between them. ...[T]his has nothing to do with some substance... It's just difference between those two things. ...[T]his is the quantity that is... being measured by my watch..."

"[T]his is very different from the Newtonian picture where Newton presupposes there's a river of time flowing, that is there before anything is put into it. ...[T]he things are there first, and the time is deduced from it afterwards."

"[A NOW] has no duration. ...[I]t's absolutely instantaneous. There is no thickness to it. Nothing changes. ...So these s, in one sense, are truly eternal, because they never change, and on the other hand, because nothing changes, they are experienced as a flash. ...[It]'s a nice contradiction... [T]he eternal is experienced as a flash, because nothing changes."

"There is nothing in between... [NOWs]. Each are separate snapshots. ...These [real photographs] ...are not changed by ...reversing the order ...It may be convenient for ...for the way we think about the world and for ordering our experiences, to suppose that these come in a certain order; but ...the picture is not changed... the snapshot is... self-contained."

"[W]hat we call yesterday is self-contained and has its experience of being yesterday, and today has memories of yesterday; and therefor I say that it's later... but each is completely self-contained, and there's no reason why you should put one... here, and another one there..."

"How do you define duration? What does it mean to say that a second today is the same as a second tomorrow? Newton in his... Principia... 1687, gave a... definition of absolute time, which he says flows uniformly without relation to anything external... [H]e says... if nothing... were to happen in the universe... if everything froze... time would still pass uniformly. ...[S]o ...time exists before anything else..."

"Richard Feynman... said, "Time is what happens when nothing else does." ...[T]hat's ...not the right way to think about time."

"[I]n 1898... Henri Poincaré wrote... "On the Measure of Time" and he said... there are two fundamental problems to do with time. One... with the definition of duration... What does it mean to say that a second today is the same... [H]e said there's another issue... [not] so widely recognized. ...[H]ow do you define simultaneity at spatially separated points?"

"He... explain[ed] how the astronomers... had to grapple with the problem of defining definition, because for 2 1/2 millennia there had been just one standard of time... the rotation of the earth. ...[T]hat had provided an incredibly accurate clock. It's... lost only a few hours in 2 1/2 thousand years. ...Very easy to use. Astronomers only... had to glance at the night sky, at the... Big Dipper... to tell the time within a minute or two... But in the 1890s a crisis developed when they found that using the earth... and... Newton's laws of motion and gravity... the Moon was speeding up. ...[T]hey thought ...the earth was slowing down because of the tidal effects of the moon... and... this would mean that the earth was not a good timekeeper at the accuracy that they wanted."

"Poincaré clearly posed these two problems and... seven years later... independently... Einstein and Poincaré... solved... the problem of defining definition at spatially separated points..."

"Einstein... revealed... extraordinary things... [H]is space and time seem to be knit together in a way you can't pull them apart... [S]omeone moving relative to me at any speed would... divide space and time in different ways... [T]he huge excitement about simultaneity meant that the... issue of duration has... been forgotten..."

"Wheeler argued that anything physical... derives its... existence... from discrete detector-elicited information-theoretic answers to yes or no quantum binary choices: bits."

"[T]hings, not information, are primary. ... 'bit' derives from 'it'."

"I argue... this weakens but not necessarily destroys the argument that nature is fundamentally digital and continuity an illusion."

"Ontological primacy should not be given to information but to things, as has always been the standpoint of realists."

"I find no reason to reverse the standard assumption of physics... what we experience can be explained by the assumption of an external world governed by law."

"It is a mistake to believe that the digits 0 and 1, being abstract, represent the immaterial. Quite... the contrary... they stand for something quintessentially concrete."

"Greek astronomers observed intricate motions of the sun, moon, and planets on the two-dimensional sky. They explained them—saved the appearances—by positing simple regular motions... in three dimensions. The success... [was] brought to a triumphant conclusion by Kepler..."

"Shannon information... [which] he also called entropy or ... involves things (...Shannon ...messages) and probabilities for those things."

"[[Symbols|[S]ymbols]] have no meaning if divorced from the entities that they represent."

"The concepts of message and probability enable one, for a definite source of N messages, to define Shannon’s information. If p_i,\quad i = 1, 2, ..., N, is the relative probability of message i and \log p_i is its base-2 logarithm, then the information I of the given source is(1) \quad I = - \sum_{k=1}^N p_i \log p_i.The minus sign makes I positive because all probabilities, which are necessarily greater than or equal zero, are less than unity (their sum being\textstyle \sum_{i}^N p_i = 1, so that their logarithms are all negative."

"and variety are central to my critique of 'it from bit'. For we can only talk meaningfully about a thing, including a , if it has distinguishing attributes. The way that they are knit together, as in the taste, shape and colour of an apple, defines the structure of the thing."

"There is one metalaw of science: it cannot exist without structured things. d variety is the ground of being. That is what gives content to both science and life."

"Consider the example of a time capsule... geologists... establish[ed] detailed correlations between the structure of fossils and rocks... They concluded... an immense , vastly longer than the bible-deduced... 6000 years. They explained... a long process... in accordance with... laws of nature. They discovered ... and... present evidence for it extends today... to all branches of science, especially cosmology and genetics."

"[[wikt:stability#Noun|[S]tability]] of solids, the fossils and rocks... exist... essentially unchanged. ...[T]he configuration carries intrinsic semantic information... different intelligent beings can in principle deduce the law or process.. Support for this is is the independent discovery of evolution by natural selection by Wallis and Darwin."

"[W]e must distinguish three kinds of information: [1] Shannon’s information, the uncertainty as to which message will be selected from a source; [2] factual information, the content of such a message; and [3] intrinsic semantic information, which distinguishes a random message, or configuration, from one that carries meaning and to some extent explains its... genesis. All... have... underpinning in things."

"Shannon-type message sources could not exist if the universe were not subject to laws of nature and far from ."

"Information theory would never have got off the ground if structured things—configurations—did not exist."

"Probabilities without things are... nothings."

"If we are to speak about ontology, as opposed to efficient coding in communication channels, the most important symbol in (1) is not p for probability but i for the thing, or configuration, that has the probability p_i."

"A more serene vision of the end comes from Julian Barbour, a philosopher who has collaborated with cosmologists in building a peculiar picture of reality that he calls Platonia. In Platonia, all possible configurations of matter exist. There is no passage of time, merely a set of unconnected instants, or "nows". We experience the illusion of time because many of these nows are arranged as if they had evolved through time. Barbour thinks that the possibilities in Platonia should be infinite, and so the comforting illusion of time should be infinite too."

"[A]t least naively time has completely disappeared from the formalism. This has led to what is called the " in ", which is how to either A) find an interpretation of the theory that restores a role for time or B) provide an interpretation according to which time is not part of a fundamental description of the world, but only reappears in an appropriate classical limit. ...The most well formulated attempt of type B), which is that of Barbour, may very well be logically consistent. But it forces one to swallow quite a radical point of view about the relationship between time and our experience."

"[T]ime is not an illusion, but the flow of time is. So is change. In spacetime, the future exists and the past doesn't disappear. When we combine Einstein's classical spacetime with quantum mechanics, we get quantum parallel universes... This means there are many pasts and futures that are all real—but this in no way diminishes the unchanging mathematical nature of the full physical reality. ...[A]lthough this idea of an unchanging reality is venerable and dates back to Einstein, it remains controversial... with scientists I greatly respect expressing a spectrum of views. ...Julian Barbour argues in his book The End of Time not only that change is illusory, but that one can even describe physical reality without introducing the time concept at all."

"Each year, on December tenth, thousands of worshippers convene in to commemorate the passing of an arms dealt known as the merchant of death. The eschatological ritual features all the rites and incantations befitting a 's funeral. Haunting dirges play as the worshippers, bedecked in mandatory regalia, mourn the merchant. He is eerily present; his visage looms over the congregants as they feast on exotic game, surrounded by fresh-cut flowers imported from the merchant's . The event culminates with the presentation of gilded, graven images bearing his likeness. This ritual is the annual award ceremony, but you'd be forgiven for thinking it was an occult sacrament."

"We should be agnostic as to what the might be."

"I'm an experimentalist. I like to look at hard data. And there — string theory is a distant second to because it doesn't make any observable predictions. ... As an experimentalist, I like when a theory makes a prediction. My job is to not prove theorists right — it's to disprove everybody else."

"Friedman had suffered health problems over the years. But news of his death stunned friends and colleagues, including UCSD physicist Brian Keating, who recruited him to , and physicist-science fiction author of . The trio made up “The Three Physicists,” an informal group that periodically met to give public talks on science and philosophy. ... With Brin and Keating, he also dove into esoterica, tackling subjects such as the physics of free will."

"Many scientists are still ashamed of using the . Just as the friends of were afraid of using the name , the opponents of the anthropic principle often say that they do not want to use the 'A' in their research."

"The best available explanation of the observed uniformity of the universe is provided by inflation. However, as soon as this mechanism was proposed, it was realized that inflation, while explaining why our part of the world is so uniform, does not predict that this uniformity must extend to the whole universe ..."

"The theory of the inflationary multiverse changes the way we think about our place in the world. According to its most popular version, our world may consist of infinitely many exponentially large parts, exhibiting different sets of low-energy laws of physics. Since these parts are extremely large, the interior of each of them behaves as if it were a separate universe, practically unaffected by the rest of the world. This picture, combined with the theory of eternal inflation and anthropic considerations, may help to solve many difficult problems of modern physics, including the cosmological constant problem."

"Why is our universe so homogeneous? Why is it not exactly homogeneous? Why is it isotropic (same in all directions)? Why all of its parts started expanding simultaneously? Why is if flat (Ω = 1)? Why is it so large? Answered by inflation"

"... We live for a while in some state which is called ... there is no preferable coordinate system ... there is no preferable choice of time ..."

"The University of Texas in Dallas has kept me at the nearest possible level to nothing."

"Pure math is rather a farce … physics is really super."

"Love is the ultimate thing, I want that to be the connection between everything I do: science, art, or otherwise."

"I paint mostly black people because I am black...I think it’s a cultural crisis in America, how people see themselves, and I think that should be an ambition in any art form to uplift people in some way."

"It’s the strangeness of the universe that has always been my favorite part of physics."

"Astronomers are masters of light; light we can see and most of which we can’t see."

"Pursue your love. Stay hopeful. You’re needed. (Responding to the question "If there was a word you could give to other young people of color who want to be scientists, what would you tell them?")"

"I grew up in an environment where love for my people and for our culture was expressed all around me. I was raised to identify with Black people around the globe."

"Astronomers are experts on understanding what light is. We can’t touch or sense most of the objects that we study, other than from the light that we receive from them."

"Everyone’s captivated by astronomy, by the stars, what’s out there in the universe...And so I made a conscious choice a long time ago that I wanted to share my work with the community, with Black folks and other people of color, especially."

"One strong motivation [for painting portraits] has been wanting to portray Black people in all the beauty that I see in them...I take a lot of joy in that."

"It’s frustrating for me, when people just talk about things at a superficial level and then try to solve the problem through diversity programs."

"We can never make assumptions about the entire universe based on what’s happening in our own backyard...we don’t want to have a theory of star formation just for the Milky Way — we want a universal theory."

"We know that molecular clouds are elaborate, and that their complex geometry is tied to star formation. But the images we have of them are flat — they’re inherently two-dimensional."

"Imagination is a huge part of what it means to do science, and I often imagine what it would be like to be up close to these environments."

"... part of the challenge with astronomy is that images are inherently flat... 3-D models uniquely tap into the human brain’s ability to detect patterns. And so that was the idea behind the 3D printing was to have a new way of visualizing stellar nurseries — visual."

"Now, most astronomers hate dust; dust can dim the light from background stars and galaxies that we're trying to observe. But I love dust. Stellar nurseries are dusty. And we can use our knowledge of dust to understand the structure of molecular clouds. Stellar nurseries are threaded by these long, dense noodlelike structures called filaments. Embedded within filaments are these compact knots of gas called cores — the final stage before star formation."

"The link between art and science for me is my love of color and my love of light."

"We talk about how diversity will open up new possibilities, and she’s a prime example of that. She thinks of stuff that no one has done and does it—pulls it off."

"It is argued that if extraterrestrial intelligent beings exist, then their spaceships must already be present in our solar system."

"The biologists argue that the number of evolutionary pathways leading from one-celled organisms to intelligent beings is minuscule when compared with the total number of evolutionary pathways, and thus even if we grant the existence of life on 109 to 1010 planets in our Galaxy, the probability that intelligence has arisen... [there] on any planet but our own is still very small. I agree..."

"[T]he probability of the evolution of creatures with the technological capability of interstellar communication within five billion years after the development of life on an Earth-like planet is less than 10-10, and thus we are the only intelligent species now existing in this Galaxy."

"The basic idea... is straightforward and... has led other authors, such as Fermi... Dyson... Hart... Simpson... and Kuiper & Morris... to conclude that extraterrestrial beings do not exist: if they did exist and possessed the technology for interstellar communication, they would also have developed interstellar travel and thus would already be present in our solar system."

"[A]n intelligent species with the technology for interstellar communication would necessarily develop the technology for interstellar travel, and this would automatically lead to the exploration and/or colonization of the Galaxy in less than 300 million years."

"[T]hat any intelligent species which develops... interstellar communication will also have... rocketry... is... a consequence of the principle of mediocrity... (that our own evolution is typical)... [T]he human species developed rockets 600 years before... radio waves..."

"[I]t seems likely that a species engaging in interstellar communication would possess a fairly sophisticated computer technology. ...Sagan has asserted that 'Communication with extraterrestrial intelligence... will require... computer actuated machines with abilities approaching... intelligence'."

"I shall assume that such a species will... develop a self-replicating universal constructor with intelligence comparable to the human level—such a machine should be developed within a century, according to the experts...—and... combined with present-day rocket technology would make it possible to explore and/or colonize the Galaxy in less than 300 million years, for an initial investment less than the cost of operating a 10 MW microwave beacon for several hundred years, as proposed by SETI..."

"It is a deficiency in computer technology, which prevents us from beginning the exploration of the Galaxy tomorrow."

"What one needs is a self-reproducing universal constructor... a machine capable of making any device... capable of making a copy of itself. Von Neumann has shown... that such... is theoretically possible, and... a human being is a universal constructor specialized to perform on the surface of the Earth."

"The payload of a probe to another stellar system would be a self-reproducing universal constructor with human level intelligence (...a von Neumann machine) together with an engine... travelling... within the stellar target system—[the engine] could be an electric propulsion system... or a ..."

"[M]aterials [to reproduce the von Neumann machine] should be available in virtually any stellar system—including systems—in the form of meteors, asteroids, comets, and other debris from the formation of the stellar system. ...[M]aterial in asteroids are highly differentiatied; many... are largely nickel-iron, while others contain large amounts of hydrocarbons."

"As the copies of the space probe were made, they would be launched at the stars nearest the target star. When these probes reached these stars, the process would be repeated... until the probes covered all the stars of the Galaxy."

"[T]he von Neumann machine would be programmed to explore the stellar system... and relay information... back to the original solar system..."

"Even if there were no planets in the stellar system... the... machine could be programmed to turn some of the material into an O'Neill colony..."

"[T]he information to manufacture a human being is contained in the genes of a single human cell. Thus if an extraterrestrial intelligent species possessed the knowledge to synthesize a living cell—and... experts assert... the human race could develop such knowledge within 30 years—they could program a von Neumann machine to synthesize a fertilized egg cell of their species. If they possessed artificial womb technology—and such... is in the beginning stages... on Earth... they could... synthesize members of their species... As suggested by Eiseley... these beings could be raised... by the robots... free to develop their own civilization..."

"[T]he problem of interstellar travel has been reduced to... transporting a von Neumann machine to another stellar system. This can be done even with present-day rocket technology."

"Hunter has pointed out that by using a Jupiter swingby to approach the Sun and then giving a velocity boost at perihelion, a solar system escape velocity... is possible with present-day chemical rockets... [M]ost other stars should have planets (or companion stars) with characteristics sufficiently close to... the Jupiter-Sun system to use this launch strategy in reverse to slow down in the other solar system."

"[T]hus... any intelligent species would develop at least the rocket technology capable of... a travel velocity ves of 3 x 10-4c. At this velocity the travel time to the nearest stars would be between 104 and 105 years. This... would necessitate... self-repair capacity... Nuclear power-souces would supply the power... If power utilization during the free-fall period was... low, even chemical reactions could supply the power."

"As ves is of the same order as the stellar random motion velocities, very sensitive guidance would be required... not... an insuperable problem with the assumed level of computer technology."

"[A] von Neumann cannot become obsolete... instructed by radio to make the latest devices..."

"Once the exploration and/or colonization of the Galaxy has begun, it can be modeled... by the mathematical theory of island colonization... developed... by MacArthur & Wilson... since... islands... are closely analogous to stars in the heaven, and von Neumann machines are even more closely analogous to biological species."

"The probability that intelligent life which eventually attempts interstellar communication will evolve in a star system is usually expressed by the :p = f_pn_ef_lf_if_cwhere f_p is the probability that a given star system will have planets, n_e is the number of habitable planets in a solar system, f_l is the probability that life evolves on a habitable planet, f_i is the probability that intelligent life evolves on a planet with life, and f_c is the probability that an intelligent species will attempt interstellar communication within 5 billion years after the formation of the planet..."

"The problem with the Drake equation is that only f_p—and to a lesser degree n_e— is subject to experimental determination... [O]ne must have a fairly large sample; for f_l, f_i, and f_c we have only... the Earth. However, if... any intelligent species... will begin... galactic exploration within 100 years after developing... interstellar communication... the sample size is enlarged... Since f_p—and n_e can... be determined by direct astrophysical measurement, the fact that extraterrestrial intelligent beings are not present in our solar system permits us to obtain a direct astrophysical measurement of an upper bound to... f_lf_if_c, which depends only on biological and sociological factors."

"This argument assumes that the five probabilities... do not vary rapidly with galactic age. The available astrophysical evidence and most theories of the formation of solar systems indicate... this... is valid."

"The factors f_lf_if_c should not depend strongly on the evolution of the Galaxy... and so can be regarded as constants. Since the Galaxy is between 11 and 18 billion years old, the number N of stars older than 5.3 billion years is about twice the number of stars formed after the Sun, and thus approximately equal to the number of stars in the Galaxy, 1011. Thus p \leqslant 10^{-11}. If we accept the usual values of f_p=0.1 to 1 and n_e = 1 found in most discussions... then f_lf_if_c \leqslant 10^{-10}. The number of communicating civilizations now existing in our Galaxy is less than or equal to p x (number of stars in galaxy) = 1; that is to say, us."

"I shall provide a physical foundation for eschatology—the study of the ultimate future—by making the physical assumption that the universe must be capable of sustaining life indefinitely... for infinite time... [W]e have to have some theory for the future of the physical universe—since it unquestionably exists— and this is the most beautiful postulate: that total death is not inevitable. All other theories of the future necessarily postulate the ultimate extinction of everything... there is nothing uglier than extermination. We physicists know that a beautiful postulate is more likely to be correct than an ugly one. Why not adopt the Postulate of Eternal Life, at least as a working hypothesis?"

"Paul Dirac was the first physicist to argue for the Postulate of Eternal Life: "With my assumption... life need never end. There is no decisive argument for dediding between [certain] assumptions. I prefer the one that allows the possibility of endless life. One may hope that some day the question will be decided by direct observation."

"[T]he eternal life assumption... implies... there must exist in this future (but in two precise mathematical senses, also in the present and the past) a Person Who is simultaneously transcendent to yet immanent in the physical universe of space, time, and matter. In the Person's immanent temporal aspect... changing (forever growing in knowledge and power), but in the... transcendent eternal aspect, forever complete and unchanging. How this comes about as a matter of physics will be described..."

"[I]s the God (...Person ...) the God? ...the uncreated Creator of the ...universe ...Who exists necessarily ... i.e., the Person's nonexistence would be a logical contradiction."

"Only if God is not in any sense contingent can one avoid regress posed in the query, who created God?"

"The Omega Point is in essence the Tillich-Pannenberg God: Being itself, but the mode of Being is futurity. This establishes the Omega Point as the God... there cannot be more being than all Being..."

"[T]his necessary existence... and omniscience... can... be consistent with... free will... by showing that... William James's definition of and free will might be physically realized in . This physical indeterminism can arise only in the context of quantum gravity... completely different from the "indeterminism" arising from the uncertainty principle. (Nonrelativistic quantum mechanics is... deterministic)"

"This new... physical indeterminism was... discovered in the 1980s and is... a consequence of Gödel's Incompleteness Theorem"

"One avoids... contradiction between contingency and necessity by avoiding... sharp distinction between God and... reality. This... distinction... leads to gnostic heresy: ...a wholly other God... divorced from our ...world. It also leads... to the Problem of Evil... naturally resolved in the Omega Point Theory."

"Wolfhart Pannenberg... suggested... there may exist a... universal physical field (analogous to Teilhard's "radial energy")... as the source of all life, and... identified with the Holy Spirit. ...[T]he universal wave function... is a... field with the essential features of Pannenberg's... "energy" field. ...If this identification is made ...as a matter of physics ...God is in the world, everywhere... with us... at all times."

"The in its counts as a person because, at any time in our future, the collective information processing system will have generated, or will be able to generate, subprograms which will be able to pass the ; high intelligence will be required at least collectively in order to survive in the increasingly complex environment near the final state."

"[T]he human-type mind is a manifestation of an extremely low level of information processing... Nevertheless, the Omega Point is still a Person... because a Being with Its level of computer capacity could easily create a Turing-Test-passing subprogram to speak for it. ...[O]ur resurrected selves probably will interact with such a program... For lack of a better term, I shall refer to the total universal information processing system in existence at any given global time as the "universal mind.""

"There is an interesting connection between my claim that the Omega Point is a Person because it contains a Turing-Test-passing subprogram, and the Christian notion of Person, as this word is applied to God. In classical Greek, the word prosopon (πρόσωπον)—persona is the Latin equivalent—primarily meant "face" or "countenance," but the word also meant a mask that an actor wore to indicate the character... By the fourth century A.D. ...this word had come to refer to those innate aspects of the human mentality which differentiate one human being from another. Today the word... refers to the total individual human mind, including the innate and learned aspects... [T]o interact with us human beings as a Person... the Omega Point would be revealing only a miniscule portion... a Person in the original sense and in the fourth century sense... '."

"It would... not be... inaccurate to regard one of the subprograms of the universal mind in the far future, one with a Turing Test-passing subprogram, as an "angel.""

"[I]nclusion of the whole past, present, and future universal history in the Omega Point is more than a mere mathematical artifact. ...[T]he Omega Point "experiences" the whole of universal history "all at once.""

"[W]e cannot "see" a person who lived a few centuries before, because the light rays... have... left the solar system. Conversely, we cannot "see" the Andromeda galaxy as it now is, but... as it was 2 million years ago. So we experience as "simultaneous" the events on the boundary of our past ... But all timelike and lightlike curves converge upon the Omega Point. ...[L]ight rays from all people who died... from all... people now... from all [future] people... intersect there. The light rays... from people... are not lost forever... [T]hese rays will be intercepted and intercepted again, by the living beings who... engulfed the physical universe near the Omega Point. All the information which can be extracted from those rays will be extracted at the instant of the Omega Point."

"The germ theory was resurrected... by Pasteur and his new medical physics. Thus... physics had to be extended to medicine in order to save the germ theory. Similarly, for religion to survive, physics must be extended into theology."

"With the introduction into physics of the Dirac/Dyson Eternal Life Postulate, science has taken the last independent stronghold of theology."

"[T]he claim that the central concern of religion is nonsense. Throughout human history, the central concern of religion has been human self-interest. In the Judeo-Christian-Islamic tradition, all morality has been obtained from declarative sentences of the form "Thou shalt not kill—because you'll go to Hell if you do!" In the Hindu-Buddhist tradition... "...—because you'll be born as a cockroach if you do!" ...In both cases, the appeal is to physics, not to fundamental moral postulates."

"The essential difficulty with divorcing morality from facts is that... there would be no way to resolve moral disputes. Morality would... be... a matter of taste... [I]n... so-called disputes over morality there is... no disagreement over fundamental moral principles, only... over facts. ...[C]onsider ...the abortion issue. There is no dispute over "Thou shall not kill,"... only... whether a fetus is a "person.""

"It is often said that the central concern of religion is an attempt to answer... "What is the relationship between humanity and the universe (and/or God). I agree... the factual answers... led to the ethical norms of... religions. The sharp distinction between fact and value which is common in twentieth-century philosophy and in the West was not present in the traditional religions. ...[T]his sharp distinction is ...contrary to the continued existence of science ...The growth and existence of science require certain ethical norms: for example, THOU SHALT NOT IMPOSE YOUR THEORIES ON OTHERS BY FORCE. Only persuasion, based on rational argument and experimental results, is allowed."

"[T]o really test the Theory, we will need the upgrade and either the SSC—the Texas Supercollider—or the European LHC. ...[P]erhaps it would be worth several billion dollars to establish that God exists, and that one day we will all be resurrected to live forever with Him/Her."

"ouch—what a disappointment! Nothing prepared me for just how B-A-D it is."

"I really admired Barrow and Tipler's Anthropic Cosmic Principle, and now... it's clear how much of the actual wordcraft... was the work of Barrow."

"I don't have any trouble... imagining nanotechnology, von Neumann probes, AI exceeding human intelligence within 50 years, or the biosphere expanding to fill... the universe. But none of that is new, and Tipler tells it less clearly than others..."

"[U]nless I'm missing something, the wheels fall off Starship Eternity."

"I noted many apparent gaping holes in his arguments or assumptions of facts contrary to the best available knowledge... [V]irtually all... dismissed with the all-purpose argument: "...ruled out by the Omega Point Boundary Condition.""

"[W]hy worry about a big rock hitting the Earth, destruction of the biosphere by inadvertent human action, accidental nuclear war..? Surely the Boundary Condition rules out those much smaller worries... Don't worry; be happy."

"[H]ow... information will be reconstituted that will allow... resurrection of the dead. ...[N]o information has been lost (the black holes having been popped by a semi-mystical process...) ...admitting that opacity and thermalisation of information may present a bit of a problem ...we'll just ...conjure up a computer with a storage capacity of 101070 bits ...and to Hell with the lost information..."

"Ok, the visible universe has around 1080 particles in it. The universe at Tipler's point of maximum expansion is, say, 10,000 times bigger... But... we're not using mere matter to store bits anymore. We're using (drumroll) the Higgs field... And when will this happen? ..."between 10−1010 and 10−10123 seconds before the Omega Point is reached". Whew, saved by the Gong of Doom."

"And how are we going to use the Higgs field to compute, organise information systems out of free quarks and pure energy... the Boundary Condition Postulate... that says that on Easter Day, 2001, Jesus Christ will return, raise the dead, etc. ...inevitable."

"I take the last existing copy of the complete works of Tipler and heave it across the event horizon of my TidyTrash&#8482; home black hole."

"Tipler's Taub universe event horizon can opener makes the black hole horizon go away. What about the singularity? ...[Y]ou now have a very large number of naked singularities... converging toward the Omega Point, which should make things even more interesting for the universal brain emerging there."

"Suppose there were a computer... which could run a completely faithful simulation of me—even a simulation at the quantum level so good the Pauli Exclusion Principle wouldn't let us in the same room. Would it be me? Would my consciousness somehow be shared..."

"[H]ow would this work if the brain and computer were separated by several light years? And if not, then what difference does it make if 1032 years of death intervene before the simulation begins to run? ...continuity of consciousness?"

"What a pile of crap."

"The review in Nature called POI a "masterpiece of pseudoscience". ...I don't think it's that good."

"The mechanics of 'steering' the universe to the omega point require actions to be taken throughout space. ...[I]ntelligences will have to spread all over the universe in time to make the first necessary adjustments. This is one of a series of deadlines that Tipler has shown that we would have to meet—and he has shown that meeting... them is, to the best of our... knowledge, physically possible."

"Tipler makes the point that the science of cosmology has tended to study the past... of spacetime. But most of spacetime lies to the future... Existing cosmology does address the issue of whether the universe will or will not recollapse, but... there has been very little theoretical investigation of the greater part of spacetime. ...[T]he lead-up to the has received far less study than the aftermath of the Big Bang. Tipler sees the omega-point theory as filling that gap. ...[It] deserves to become the prevailing theory of the future of spacetime until and unless it is experimentally (or otherwise) refuted. (Experimental refutation is possible because the existence of an omega point in our future places certain constraints on the condition of the universe today.)"

"Tipler makes... additional assumptions—some plausible, others less so—which enable him to fill in more details of future history. ...[His] quasi-religious interpretation... and his failure to distinguish that... from the underlying scientific theory, that have prevented the latter from being taken seriously."

"Tipler notes that an infinite amount of knowledge will have been created by the time of the omega point. He... assumes... the [far future] intelligences will, like us, want (or... need)... knowledge other than... necessary for... survival. ...[T]hey have the potential to discover all [physically knowable] knowledge, and Tipler assumes that they will do so. So in a sense, the omega point will be omniscient."

"Tipler makes use of a handy linguistic device... common in mathematical physics... misleading if taken too literally. ...[T]o identify a limiting point of a sequence with the itself. ...What he does not mean is that there is that there is a knowing entity literally at the end point of ... there is no physical entity there at all. Thus... the knows nothing, and can... exist only because some... explanations... refer to the limiting properties of physical events..."

"Tipler uses the theological term 'omniscient'... but... The omega point will not know everything. The overwhelming majority of abstract truths... will be inaccessible to it as they are to us."

"Tipler says, it will be omnipotent. But... this... is not absolute. ...[I]t is strictly limited by the available matter and energy, and is subject to the laws of physics."

"Since the intelligences in the computer will be creative thinkers, they must be classified as "people". ...And so he claims... at the omega-point limit... an omniscient, omnipotent, omnipresent society of people. This society, Tipler identifies as God."

"[P]eople near the omega point could not... communicate their wishes to us, or work miracles (today). They did not create the universe... [nor] invent the laws of physics—nor could they violate those laws... They may listen to prayers... (perhaps by detecting very faint signals), but they cannot answer them. They are... opposed to religious faith, and have no wish to be worshipped. ...But Tipler ...argues that most of the core features of the God of the Judeo-Christian religions, are... properties of the . Most religious people will... disagree..."

"In his enthusiasm... Tipler has neglected part of the Popperian lesson about what the growth of knowledge must look like. If the omega point exists, and if... created in the way... Tipler... set out... the late universe will... consist of embodied thoughts of inconceivable wisdom, creativity and sheer numbers. But... problem solving means rival s, errors, criticism, refutation and backtracking. Admittedly, in the limit (which no one experiences), at the instant the universe ends, everything that is comprehensible may have been understood. But at every finite point our descendants' knowledge will be riddled with errors. Their knowledge will be greater, deeper and broader than we can imagine, but they will make mistakes on a correspondingly titanic scale too. Like us, they will never know certainty or physical security, for their survival, like ours, will depend on... creating a continuous stream of new knowledge. If they... fail, even once... to increase... computing speed and memory capacity... the sky will fall in on them and they will die. Their culture... will be split by passionate controversies. ...[I]t seems unlikely that it could... be regarded as a 'person'. Rather... a vast number of people interacting... disagreeing. ...often ...mistaken, and many mistakes ...uncorrected for... long periods (subjectively). Nor... ever... morally homogeneous...Nothing will be sacred... and... people will continually be questioning assumptions that other[s]... consider... fundamental moral truths. ...[B]y the methods of reason, every... controversy will be resolved. But... replaced by... more... fundamental controversies. Such... is very different from... God... But... some subculture within it... will be resurrecting us if Tipler is right."

"[I]f the observed acceleration were to continue forever, the Theory would be refuted. But the expansion of life to engulf the universe is EXACTLY what is required to cancel the positive cosmological constant (a.k.a. the Dark Energy)..."

"The Omega Point Theory suggests that the particle physics Standard Model (SM) is sufficient to explain both [dark matter and dark energy]: the Dark Energy is just the currently uncancelled part of the positive cosmological constant, and the Dark Matter is just the Standard Model SU(2)_{left} field, coupled to the SM Higgs field. I was very worried when I wrote PHYSICS OF IMMORTALTIY that the entropy in the CMBR would make an acceleration in the collapsing phase of universal history impossible. I propose to solve this problem by claiming the temperature of the CMBR — currently "measured"... 2.2726 degrees — is actually... ! I show in a paper I put on the lanl data base (xxx.lanl.gov) last November that such an apparently ridiculous claim is possible, because any quantized gauge field in a homogeneous and isotropic universe would NECESSARILY have a Planckian spectrum, even at zero temperature! What the measurements of CMBR showing that it is Planckian... are really measuring... not the temperature, but the size of the universe. In my paper, I show how to convert the... "temperature" of 2.2726 into the size of the universe."

"I relate deeply to Tipler’s... concept that future technology may... resurrect the dead... by... "copying them to the future" and... allow myself to contemplate such possibilities. There may be a point where consciousness becomes a important factor in the destiny of the universe, where conscious beings develop the capability to choose and build the universe they want to inhabit, and invite the dead of past ages to join the party by copying them to the future. ...[T]his soft rationalist, high level and not detailed concept ...will, I hope, be detailed and realized by future scientists and engineers."

"Tipler has been criticized... for mixing religion with science. ...also ...for making wrong scientific assumptions. ...[I]t appears that the is accelerating and ...left to itself, will never enter the phase ...a prerequisite for the scenario ...Tipler is certainly wrong on many points that will be corrected by future scientists. But dismissing him as a crank is... like dismissing Leonardo as a crank because his aircraft sketches wouldn’t fly..."

"The Physics of Christianity... received... bad reviews from very smart people like John Walker."

"s and massive s in the mass range 2–20 have been proposed as candidates to provide the in the halo of our galaxy."

""What is the Universe made of?" The question is one of the deepest unanswered mysteries in all of human existence. Solving the puzzle has been my life's work and is the hottest research topic in cosmology and particle physics today."

"... On my father’s side, I come from a family of artists and architects. My grandfather was a Bauhaus architect in Germany and my grandmother was a painter. When my father as a child was tinkering around in the basement with chemistry sets, his mother said to him, “You’ll never make a living in science. Why don’t you go into the family business, the arts?” Well, he defied that advice. He was actually a PhD student with Heisenberg in Göttingen, and then a post-doc with Enrico Fermi in Chicago. After that he went to Caltech where he switched to biology and became one of the founders of the field of molecular biology. He founded the department of molecular biology at the . My mother was from a town on the Swiss-German border called , and she actually got her PhD in biology at age 22."

"... in the seventies the work of and Rubin ... looked at galaxies and found evidence for dark matter in every single one."

"The universe is filled with thermal radiation having a current temperature of 2.75 K. Originating in the very early universe, this radiation furnishes strong evidence that the Big Bang cosmology best describes our expanding universe from an incredibly hot, compacted early stage until now. The model can be used to extrapolate our physics backward in time to predict events whose effects might be observable in the 2.75 K radiation today. The spectrum and isotropy are being studied with sophisticated microwave radiometers on the ground, in balloons, and in satellites. The results are as predicted by the simple theory: the spectrum is that of a blackbody (to a few percent) and the radiation is isotropic (to 0.01 percent) except for a local effect due to our motion through the radiation."

"David Todd Wilkinson died on 5 September 2002 in Princeton, New Jersey, after having battled cancer for 17 years. His role in the measurements of the thermal (CMB) was key to the completion of the program of cosmological tests that began with Edwin Hubble’s discovery of the expanding universe in 1929."

"The Cosmic Background Explorer (COBE) satellite, under study by NASA since 1976, will map the spectrum and the angular distribution of diffuse radiation from the universe over the entire wavelength range from 1 micron to 1.3 cm. It carries three instruments: a set of differential s (DMR) at 23.5, 31.4, 53, and 90 , a far infrared absolute (FIRAS) covering 1 to 100 cm-1, and a covering 1 to 300 s. They will use the ideal space environment, a one year lifetime, and standard instrument techniques to achieve orders of magnitude improvements in sensitivity and accuracy, providing a fundamental data base for cosmology. The instruments are united by common purpose as well as similar environmental and orbital requirements. The data from all three experiments will be analyzed together, to distinguish nearby sources of radiation from the cosmologically interesting diffuse background radiations."

"NASA’s Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the and discovering the . ... The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post–Big Bang objects is twice as great as previously believed."

"… the technical question was, “Is the Big Bang the right story? Is the expanding universe the right story?” And there are a lot of sub-questions in that. If it is the right story, then how did the galaxies come? Where did they come from? Because it seemed quite mysterious. People were just beginning to realize that there was a structure that had been seen in the maps of where the galaxies are located, and that we had no clue what made that happen. So what is there to measure? Well, there’s not very many things to measure. You can measure the galaxies or you can look for this cosmic background radiation. And if you could measure it, it would tell you something that you never knew before."

"I think . I never would have guessed it. Even as an undergraduate, once I’d learned a little physics, I would have thought that the universe was eternal, static, and always in equilibrium. So in graduate school when I found out that the universe was expanding, I was awestruck. Then I learned if we could measure the expanding universe, the way we record the growth of a child with marks on a doorframe ... , we could determine the age of the universe and predict its ultimate fate. This was staggering! I knew this is what I wanted to do. Since that time, charting the expanding universe to determine its nature has been my passion. Though I have to add: knowing what I know now, that the , I feel like King Alfonso X of Castile who saw Ptolemy’s and reportedly said “If the Lord Almighty had consulted me before embarking on creation thus, I should have recommended something simpler.”"

"Today we are able to make very precise measurements of the by measuring the distances and s of . The shift in a supernova’s due to the expansion of space gives its redshift (z) and the relation between redshift and distance is used to determine the expansion rate of the universe. Supernovae with greater redshifts, lying at greater distances, reveal the past expansion rate as their light was emitted at an epoch when the universe was younger. Supernovae Type Ia were the suitable candidate for these measurements as you need objects that are very luminous (thus can be observed even when they are very far) and highly uniform (so that intrinsic scatter doesn't blur the signal). Supernovae Type Ia are the most luminous of the common supernova types, peaking at 4 billion , and thus allowing us to look at extreme large distances."

"is about the gravity of empty space, the gravity of the vacuum. And the vacuum is a concept that we address in and quantum mechanics. Quantum mechanics is physics on microscopic scales, while Einstein's theory of general relativity ... is physics on macroscopic scales. These two theories are both great, but they don't work together. We don't have what's called a quantum theory of gravity, the way the two are united. However, dark energy actually requires you to use both of these branches of physics. So our hope is that by observing how the universe actually does physics at that interface, we will learn how to unify those."

"Less than a century ago we had no idea that there was more to the universe than our own Milky Way. the immense size of the universe, the fact that it is expanding, the fact that it is populated with such things as – all this and more had to be discovered before we could do the work that led us to contemplate an ."

"Not only does it swallow anything that comes too near it but no one lives to tell the tale ... there are footprints leading in, and no footprints leading out ... If black holes weren’t real, I think the science-fiction writers would have wanted to invent them."

"Having that bit of diabolical contrariness is a weird pleasure of being a scientist. You’re always trying to figure out, “OK, how could I be fooling myself into a wrong conclusion?” Because the more you get those things right, the more chances you have of catching the universe doing something that our brains never would’ve imagined. Scientists build out of what seems like a stance of weakness. So, one might think it’s terrible that scientists are always discovering new ways that they’re wrong, or it’s terrible that they’re only probabilistically sure of facts. But that’s really where scientists’ superpower has come from. We have been able to figure out amazing solutions to problems or surprises about the world. Much of that can be traced back to being willing to be wrong and being comfortable with finding the ways you’re wrong. And for this purpose, you want to build strong relationships with people who are going to tell you when you’re wrong, who will disagree with you, or who compete with you. They’re your best bet at figuring out where you’re making a mistake."

"As we discover , we suffer from a variety of s, both in our nearby and distant searches. The most significant effect is – a selection effect which leads brightness limited searches finding brighter than average objects near their sensitivity limit. This bias is caused by the larger volume in which bright objects can be uncovered compared to their fainter counterparts. Malmquist bias errors are proportional to the square of the intrinsic dispersion of the distance method, and because SN Ia are such accurate distance indicators, these errors are quite small – approximately 2%. We use s to estimate these effects, and remove their effects from our s."

"With the as an anchor, theory converged on a standard model of the universe, which was still in place in 1998, at the time of our discovery of the . This standard model was based on the theory of general relativity, and two assumptions. assumption one was that the , and assumption two that it is composed of normal , i.e. matter whose density falls directly in proportion to the volume of space, which it occupies. Within this framework, it was possible to devise observational tests of the overall theory, as well as provide values for the fundamental constants within this model – the current expansion rate (), and the average density of matter in the universe. For this model, it was also possible to directly relate the density of the universe to the rate of cosmic deceleration and the geometry of space. it stated that the more material the faster the deceleration, that above a critical density the universe has a and below this a ."

"… one does not expect a . To my mind, I was genuinely surprised because when you make a discovery of acceleration–well, what causes the acceleration? Well, we give it a name–'–but we don’t understand it yet. I would not be surprised if we don’t understand it during my lifetime. Without understanding it, I felt it wouldn’t be worthy of a Nobel Prize. The fact that it was given pretty timely–you know, I was only 44 last year–was a bit of surprise."

"Being a woman is hard ... The expectations are that we’ll be gorgeous, completely organized, great mothers, great wives, and great professionals ... The pressures are huge. I was always expected to bring the cookies to meetings because I’m a woman. Like, men can’t find cookies? That’s why I say: Let’s be nicer to ourselves. Diversity is very important ... When you bring in new folks who ask new questions, you change the field and the basic sciences. Women want to do great research. But we’re asking, ‘Why do we have this rule? That artificial hierarchy?’ We can be more collaborative. And I’ll tell you this ... When men suggest we speak with deeper voices if we want to get our message across, here is what I say: Gravity does not care how deep your voice is."

"is that is assumed to be absolutely stable. A seed of strange matter in a will convert the star into a . The speed at which this conversion occurs is calculated. The calculation takes into account the rate at which the and s equilibrate via s and the diffusion of strange quarks towards the conversion front. The speed is found as a function of the temperature of the star and the minimum strangeness necessary for strange matter stability. The conversion can be detected as an energy release of ∼58 MeV with different luminosities for different stages of a neutron star's evolution and as a “super-glitch” on s' frequencies."

"Scientists are very curious ... We might be curious about something that looks completely irrelevant, and it turns out to be a really amazing thing. Or it could be irrelevant. We don't know. If we knew, we wouldn't be looking at it."

"I was really interested in the basic workings of nature: Why ? What is the unified theory of everything? But I realized how many easier questions we have in astrophysics: that you could actually take a lifetime and go answer them. Graduate school at MIT showed me the way to astrophysics — how it can be an amazing route to many questions, including how the universe looks, how it functions, and even particle physics questions. I didn’t plan to study s; but every step it was, “OK, it looks promising.”"

"The Of Extreme Multi-Messenger Astrophysics (POEMMA) was designed as a Astrophysics probe-class mission to identify the sources of ) and observe s from extremely energetic transient sources. POEMMA consists of two identical spacecraft flying in a loose formation at 525 km altitude oriented to view a common atmospheric volume and to provide full-sky coverage for both types of messengers. Each spacecraft hosts a wide with a hybrid focal plane optimized to observe both the UV fluorescence signal from extensive air showers (EASs) and the optical signals from EASs."

"The , which measures the , together with the total energy density of the Universe, sets the size of the observable Universe, its age, and its radius of curvature. Excellent progress has been made recently toward the measurement of the Hubble constant: a number of different methods for measuring distances have been developed and refined, and a primary project of the has been the accurate calibration of this difficult-to-measure parameter. The recent progress in these measurements is summarized, and areas where further work is needed are discussed. Currently, for a wide range of possible s, the Universe appears to have a . Combined with current estimates of stellar ages, the results favor a . They are consistent with either an , or a with a non-zero value of the ."

"We are at an interesting juncture in cosmology. With new methods and technology, the accuracy in measurement of the has vastly improved, but a recent tension has arisen that is either signaling or as-yet unrecognized uncertainties. Just under a century ago, Edwin Hubble revolutionized cosmology with his discovery that the . Hubble found a relationship between radial velocity and the distance to nearby galaxies, determining the proportionality constant Ho (=v/r), that now bears his name. The Hubble constant remains one of the most important parameters in cosmology. An accurate value of Ho can provide a powerful constraint on the cosmological model describing the evolution of the universe. In addition, it characterizes the expansion rate of the Universe at the current time, defines the observable size of the Universe, and its inverse sets the ."

"... after finishing my postdoc, I became a faculty member at , and then ended up being the scientific leader of this project to measure the rate at which the universe is expanding. ... when that project finished, .. we .. resolved the issue. We went from a factor of 2 uncertainty — we measured an uncertainty of 10%."

"For almost a century the theory of general relativity (GR) has been known to describe the force of gravity with impeccable agreement with observations. ... Far from a purely academic exercise, the existence of consistent alternatives to describe the theory of gravitation is actually essential to test the theory of GR. Furthermore the open questions that remain behind the puzzles at the interface between gravity/cosmology and particle physics such as the hierarchy problem, the old and the origin of the late-time acceleration of the Universe have pushed the search for alternatives to GR."

"After the Big Bang, the universe expanded and cooled down. And we expect this expansion to gradually slow down because the universe has things like galaxies inside it, and they are attracted to each other by gravity. But in the past 25 years or so, observations have shown precisely the opposite: The expansion of the universe is speeding up. It’s accelerating. This is the concept of , and it points to something that we are missing in our description of the universe. Dark energy is sometimes seen as this mysterious, magical source of energy that accelerates the expansion of the universe. But this isn’t really the core of the problem. We can cook something up for dark energy — just as we do for dark matter — and hope we’ll detect it later. It’s not particularly satisfying, but we do this, we’ve done it before. Really, ."

"Gravity is the reason why the Universe itself can even exist and evolve. It elevates space and time from mere pieces of scenery into central actors in the unfolding drama of reality. As we embrace gravity, we can't help but also pit ourselves against it: leaping, floating, or flying as we pursue brief moments of freedom from its command. I, for one, have been chasing gravity my entire life—seeking, like so many scientists who have come before me, to unravel its deepest mysteries."

"... we can never really shield ourselves from gravity. You can think of a for electromagnetism — where you can shield yourself from . But that is not the case for gravity. Everyone is connected through gravity."

"A theory of is one in which the , the particle that is believed to mediate the force of gravity, has a small mass. This contrasts with general relativity, our current best theory of gravity, which predicts that the graviton is exactly massless. In 2011, Claudia de Rham (), () and Andrew Tolley (Imperial College London) revitalised interest in massive gravity by uncovering the structure of the best possible (in a technical sense) theory of massive gravity, now known as the dRGT theory, after these authors. Claudia de Rham has now written a popular book on the physics of gravity. The Beauty of Falling is an enjoyable and relatively quick read: a first-hand and personal glimpse into the life of a and the process of discovery."